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MC Quiz 1
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Preguntas del test (40)
1In a US Today/Gallup poll taken shortly after the game, 64% of respondents who described themselves as baseball fans said Major League Baseball should overturn the umpire's safe call that cost pitcher Armando Gallaraga a perfect game. The poll based on 470 respondents has a margin of error of 6%. Which of the following statements best describes what is meant by the 6% margin of error?
- AAbout 6% of the baseball fans agreed with the umpire's call.
- BAbout 6% of those polled were not actually baseball fans.
- CThe difference between the sample percentage and the population percentage is likely to be less than 6%.
- DAbout 6% of the sample should not be included in the population.
- EThe difference between the percentage of people in favor of overturning the call in this survey and in a second similar survey would be less than 6%.
2A university has 12,000 female students and 8,000 male students. Fifty percent of the women use the student gym and 40% of the men use the student gym. A simple random sample of 100 students is selected. What is the expected number o students in the sample who use the gym?
- A47
- B46
- C45
- D44
- E43
3A manufacturer of batteries claims they have a shelf life of one year. The manufacturer contends that 99.5% of the batteries will function after sitting without use for one year. If the company's claim is true, what is the expected number of batteries in a random sample of 5,000 one-year-old batteries that will function?
- A4,750
- B4,925
- C4,950
- D4,975
- E4,995
4A fertilizer company is trying to convince corn farmers using a particular fertilizer that their new product CORNPLOSION will lead to an increase in yield over the currently used fertilizer. To determine which fertilizer results in a higher yield of corn, 10 one-acre fields are split into halves. The current fertilizer is used on one-half of each field and CORNPLOSION on the other half. The fertilizer that goes on the east half of the field is determined by a coin flip. The yield of the corn is measured in bushels per acre. What are the number of degrees of freedom associated with the appropriate t test for testing to see if there is a difference between the mean corn yield for the two types of fertilizer?
- A9
- B10
- C18
- D19
- E20
5A certain library has 10,000 books. Two thousand of these books are nonfiction books and the rest are fiction. In order to estimate the total number of pages in their nonfiction books, two plans are proposed.
Plan I: Sample 50 books at random. Estimate the mean number of pages per book using a confidence interval. Multiply both ends of the interval by 10,000 to get an interval estimate of the total.
Plan II: Identify the 2,000 nonfiction books. Sample 50 nonfiction books at random. Estimate the mean number of pages of nonfiction books using a confidence interval. Multiply both ends of the interval by 2,000 to get an interval estimate of the total.
On the basis of the information given, which of the following is the better method for estimating the total number of pages in nonfiction books in the library?- AChoose plan I over plan II.
- BChoose plan II over plan I.
- CChoose either plan, since both are good and will produce equivalent results.
- DChoose neither plan, since neither estimates the total number of nonfiction pages.
- EThe plans cannot be evaluated from the given information.
6To check the effect of wet road conditions on automobile stopping distances, five economy-size cars from automaker A and five economy-size cars from automaker B are tested. The same driver is used to test all cars. The driver accelerates to 50 miles per hour and then brings the vehicle to a complete stop when it reaches a white line. The cars from automaker A are tested on a dry straightway. The cars from automaker B are tested on the same track, but the track is hosed down with water before testing. The distance between the white line and where the car comes to a stop is measured for each car and the mean for the cars stopping on the dry road is compared to the mean for the cars stopping on the wet road. Is this a good experimental design?
- ANo because the means are not proper statistics for comparison.
- BNo because more than 2 brans should be used.
- CNo because road conditions are confounded with brand.
- DNo because the experiment should not be limited to economy-sized cars.
- EYes
7The box plots above summarize two data sets, A and B. Which of the following must be true?
I. Set B has a higher median than set A.
II. Set B contains more data than set A.
III. The data in set B have a larger range than the data in set A.
- AI only
- BIII only
- CI and II only
- DI and III only
- EI, II, and III
8Splatastic Paintball Range sells paintballs in bulk at wholesale prices, as well as individually at retail prices. Next year's sales will depend on market conditions, but company executives believe that the following probability distributions describe wholesale and retail sales for next year. What is the expected profit for the next year if the profit from each paintball sold for $1 for wholesale and $2 for retail?
- A$141,000
- B$144,000
- C$162,000
- D$282,000
- E$341,000
9D'Andre and Claire are both going to a Chinese buffet. Based on their previous visits to the buffet, the probability distributions of the number of plates of food they will eat are given below. Assuming D'Andre and Claire make their decisions independently, what is the probability that they will eat six plates of food combined?
- A0.04
- B0.07
- C0.10
- D0.70
- E0.80
10A survey of 84 randomly selected military officers was conducted to determine whether or not they participated in high school athletics. The two-way table shows the numbers of officers by varsity states (varsity athlete, not varsity athlete) and branch of service (Navy, Air Force,). Which of the following best describes the relationship between varsity status and branch of service?
- AThere appears to be an association, since more Navy officers than Air Force officers were varsity.
- BThere appears to be an association, since twice as many officers were varsity athletes.
- CThere appears to be no association, since the proportion of officers that were varsity athletes was the same for both Navy and Air Force.
- DThere appears to be no association, since there are fewer Air Force officers who were not varsity athletes but more Navy officers who were varsity athletes.
- EThere is not enough information to decide whether or not an association exists.
11Which is the best estimate of the standard deviation of the distribution shown below?
- A15 kg
- B20 kg
- C30 kg
- D35 kg
- E60 kg
12A window manufacturer claims that its new seal-tight system will save homeowners in cold climates $100 a month on average during the winter. A consumer group is skeptical of this claim and thinks the the manufacturer may be overstating the savings. If mu represents the true mean savings for this new window system, which of the following gives the null and alternative hypothesis that the consumer group should test?
- AHo: mu <= $100
Ha: mu > $100 - BHo: mu = $100
Ha: mu not= $100 - CHo: mu <$100
Ha: mu >= $100 - DHo: mu = $100
Ha: mu < $100 - EHo: mu = $100
Ha: mu > $100
- AHo: mu <= $100
13Stanley’s boss told him that he did not deserve a raise and that Stanley was making an amount similar to other accountants with his experience. Stanley gathered some data and found that the z-score fo his salary s compared to other accountants with the same level of experience is -1.25. Which of the following is the best interpretation of this z-score?
- AStanley makes 1.25% less than other accountants with his experience level.
- BStanley makes 1.25% more than other accountants with his experience level.
- CStanley makes $1.25 less per pay period than the average for accountants with his experience level.
- DStanley’s salary is 1.25 standard deviations above the mean salary of other accountants with his experience level.
- EStanley’s salary is 1.25 standard deviations below the mean salary of other accountants with his experience level.
14Uncle Hugo’s Electronics decided to see whether a local music CD section would be profitable at its 1,000 stores nationwide. It decided to set up local music displays at its 100 biggest locations. In this study, Uncle Hugo’s marketing department found that sale of local artists were significantly greater in stores with the local music display. Which of the following statements explains why it would not be appropriate to recommend that all of the stores should add a local music section?
I. The study only targeted Uncle Hugo’s largest locations and there may not be as much good local music available in smaller locations.
II. Only 100 stores had a local display while 900 stores did not have a local display.
III. The sample consisted of more than 5% of the population.- AI only
- BII only
- CIII only
- DI and II only
- EI, II, and III
15. Every Wednesday Burgerville has a “discount deck day.” A customer who comes in with a child may choose to pick two cards from a standard deck of playing cards. If the two cards are the same number then the child’s junior burger is free with the purchase of a megaburger. IF the two cards are the same suit, the the child’s junior burger is half price with the purchase of a mega burger. The menu price for a junior burger is $2.00 and a megaburger is $4.00. Let X represent the amount paid by a customer with a child for a junior burger and a mega burger. The expected value of X is $5.65 and the standard deviation is $0.59. If a customer with a child picks form the discount deck and purchases both a junior burger and a megaburger every Wednesday for 12 consecutive weeks, what is the total amount that the customer would expect to pay for all of the burgers?
- A$5.65
- B$56.50
- C$65.50
- D$67.80
- E$70.00
16Every Wednesday Burgerville has a “discount deck day.” A customer who comes in with a child may choose to pick two cards from a standard deck of playing cards. If the two cards are the same number then the child’s junior burger is free with the purchase of a megaburger. IF the two cards are the same suit, the the child’s junior burger is half price with the purchase of a mega burger. The menu price for a junior burger is $2.00 and a megaburger is $4.00. Let X represent the amount paid by a customer with a child for a junior burger and a mega burger. The expected value of X is $5.65 and the standard deviation is $0.59. If a customer with a child picks from the discount deck every Wednesday and buys both a junior burger and a megaburger for 5 consecutive weeks, what is the standard deviation of the total amount paid for all of the burgers.
- A$0.26
- B$0.35
- C$1.32
- D$1.74
- E$2.95
17Which of the following is not a property of all normal distributions?
I. The distribution is symmetric
II. The distribution is centered at 0.
III. The median and the mean are equal.- AI only
- BII only
- CIII only
- DI and II only
- EI, II, and III
18Before going to college, Chelsea wanted to see if she could get some pocket money by selling her old car online. She selected a sample of the bid prices on 25 similar cars sold online in the past month. Later Chelsea realized that the lowest-priced car in the sample was mistakenly recorded as half the price it actually sold for. However, after correcting the error, the corrected price was still less than or equal to any other car price in her sample. Which of the sample statistics must have remained the same after the correction was made?
- AMean
- BMedian
- CMode
- DRange
- EVariance
19The back-to-back stem-and-leaf plot below gives gives the growth in millimeters of 23 onion bulbs planted by students in Mrs. Shelton's third grade class. Which of the following statements i not justified by the data?
- AFor the plants shown, most of them grew less than 25 millimeters per week.
- BIn general, plants grew at the same rate in the first week as they did in the second.
- CThe spread between the shortest and tallest plant did not change much between the two weeks.
- DThe size of every plant increased from week one to week two.
- EThe median size of the plants increased from week one to week two.
20A carnival games requires you to make three baskets in a row to win a prize. Andre is a basketball player who normally makes 80% of his shots, but because of the trick rim, he estimates that he can only make the shot 60% of the time. Assuming that successive shots are independent, what is the probability that Andre wins a prize if he decides to play the game once?
- A0.2
- B0.216
- C0.4
- D0.512
- E0.6
21Laws have been proposed in some border states that would allow police officers to ask motorists to prove that they are U.S. citizens during routine traffic stops. If it is determined that these motorists are not in the United States legally, then they will be deported. Putting this in terms of a hypothesis test, Ho is that the motors is in the United States legally and Ha is that the motors is not in the United States legally. Which of the following is an example of a Type I error?
- AA motoris is in the country legally but does not have the paperwork to prove it in his or her vehicle and so the motorist is thought to not be in the country legally.
- BA motoris is not in the country legally but has counterfeit paperwork that fools the police and so the motorist is thought to be in the country.
- CA motorist is not in the country legally but when stopped gets deported.
- DA motoris is not in the country legally but never gets stopped by the police.
- EA motorist is in the country legally and is not sopped by the police.
22The number of people in a gym at noon on each of 60 randomly selected days produces a mean of 34.7 people and a standard deviation of 8.1 people. Which of the following is an approximate 90% confidence interval for the mean number of people in the gym at noon.
- A(26.70, 42.70)
- B(32.95, 36.45)
- C(32.65, 36.75)
- D(33.65, 35.75)
- E(34.48, 34.92)
23Mr. Branch and his son Dennis both played on their college basketball teams. Mr. Branch scored 12.5 points per game at a time when the average number o points scored by a player in college was 11 points a game and the standard deviation was 3.8 points. Dennis scored 15.8 points a game when the average number of points scored by a player in college was 14 points a game and the standard deviation was 6.1. Mr. Branch contends that while he's proud of his son, he was a better scorer compared to the players of his day than his son was compared to his contemporaries. Who is correct in saying that he did better when compared to his peers?
- AMr. Branch is correct
- BDennis is correct, they both did equally well.
- CNeither is correct, they both did equally well.
- DThere is no basis for comparison, since they played in different eras for different teams.
- EThere is not enough information for comparison, because the number of players in each era is not known.
24A die is rolled six times, and the number of times a 3 is rolled is counted. This procedure of six dice rolls i repeated 100 times and the results are summarized in a frequency distribution. Which of the frequency distributions below is most likely to contain the results from these 100 trials?
- A
- B
- C
- D
- E
- A
25An art gallery wants to conduct a survey to see what type of offerings people are most interested in. It wants to begin with a simple random sample of 50 people who have previously purchased art at the gallery. Which of the following survey methods will produce a simple random sample?
- ASurvey the 50 most recent purchasers.
- BSurvey the 50 purchasers who have spent the most money at the gallery.
- CUse random numbers to choose 10 people each who have purchased watercolors, sculptures, canvas, photographs, and mixed media.
- DHold a brunch for previous customers and put comment cards at 50 randomly assigned seats.
- ENumber a list of all people who have previously made a purchase. Use a table of random numbers to choose 50 people from this list and survey them.
26There is a linear relationship between the amount of fat in a sandwich and the amount of calories in a sandwich. A least-squares regression line was fit using some data collected by a nutritionist, resulting in the line y-hat = 217.3 + 35.2x where x is the grams of fat in the sandwich and y is the estimated caloric content of the sandwich. What is the estimated increase in calories that corresponds to an increase of 8 grams of fat?
- A35.2
- B217.3
- C281.6
- D498.9
- E1738.4
27In a test of the null hypothesis Ho: mu = 23 against the alternative Ha: mu > 23, a random sample form a normal population with a known standard deviation produces a mean of 28.9. The z statistic for the test is 2.48 and the p-value is 0.0066. Based on these statistics, which of the following conclusions could be drawn?
- AThere is convincing evidence that mu > 23
- BDue to random fluctuation, 49.34% of the time a sample produces a mean larger than 23.
- C0.66% of the time, rejecting the alternative hypothesis is an error.
- D0.66% of the time, the mean is above 23.
- E99.34% of the time, the mean is below 23.
28The weights of watermelons are approximately normally distributed about a mean of 90 ounces and a standard deviation of 15 ounces. If a watermelon is in the 96th percentile for weight, then tis weight, in ounces, is closes to?
- A26
- B105
- C116
- D126
- E262
29Ten golf carts were selected at random from a country club to be outfitted with an engine modification designed to increase their maximum rate of speed. The time needed to complete 18 holes was recorded fora group using the upgraded golf carts and a group using golf carts that had not been modified. The difference in means for the time needed to complete 18 holes was 24 minutes. With mu1 denoting the mean time for unmodified cars and mu2 denoting the mean time for modified carts, a 95% confidence interval estimate of the true difference in mean time, mu1 - mu2 is (16, 32). Which of the following statements is correct decision based on this confidence interval?
- AWe can be confident that mu1 is around 16 and mu2 is around 32.
- BThe country club should not change to modified carts because we can be confident that mu1 is greater than mu2.
- CThe country club should change to modified carts because we can be confident that mu1 is greater than mu2.
- DThe country club should not change to modified carts because we can be confident that there is no difference between mu1 and mu2.
- EThe country club should convert the modified carts back to the original engines because we are not confident that the modified carts are better.
30The equation of the least-squares regression line for a set of data is y-hat=0.68 + 1.21x. What is the residual for the point (3, 4)?
- A-0.31
- B-0.68
- C-1.52
- D-3.63
- E-4.31
31A random variable X has a normal distribution centered at 100. About 10% of the time, X takes on a value that is less than 80. What is the approximate value of the standard deviation of X?
- A10.0
- B12.2
- C15.6
- D20.0
- E40.0
32The process of packaging candy corn yields bags with varying numbers of candy pieces. The candy manufacturer claims that, on average, bags of candy corn contain 350 pieces. The consumer's Corner magazine tests a random sample of 40 bags. The mean number of pieces of candy corn for this sample is 346.8, while the standard deviation is 12.4. Which of the following describes the approximate P-value for a test to determine if there is evidence that the mean number of candies per bag is less than the candy maker claims?
- AP-value < 0.001
- B0.001 < P-value < 0.01
- C0.01 < P-value < 0.05
- D0.05 < P-value < 0.10
- EP-value > 0.10
33A survey was conducted to estimate the proportion of California workers who would rather live in a different state. In a random sample of 100 California workers, 28% indicated that they would rather live in another state. A 95% confidence interval for the proportion of all Californian workers who would rather live in another state is:
- A(0.192, 0.368)
- B(0.207, 0.353)
- C(0.230, 0.330)
- D(0.234, 0.326)
- E(0.255, 0.305)
34Which of the following represents a distribution where the mean is greater than the median?
- A
- B
- C
- D
- E
- A
35Sally realizes that all of her professors are going to give an exam of some kind in the half week that leads up to Thanksgiving break. If Sally takes four classes, and each class is equally likely to place its exam on either the Monday, Tuesday, or Wednesday before Thanksgiving break, what is the probability that Sally has all four of her exams on one day?
- A0
- B0.012
- C0.037
- D0.250
- E0.333
36A study was conducted by psychologists who wanted to determine at what age children develop their first crush. They asked college freshman to select from one of four age categories, and the results are listed in the table below. According to the two-way table, what percentage of males had their first crush before the age of 13?
- A3.4
- B18.9
- C22.4
- D34.5
- E49.1
37Which of the following is least likely to be a potential confounding variable in a study of the effect diet has on weight loss in pounds?
- AGender
- BBeginning Weight
- CTimes spent exercising
- DName
- ETime spent watching TV
38The periodic table provides an atomic mass for each element, but these figures do not prove accurate for certain isotopes of some elements. Because isotopes are likely to contain a different mix of neutrons and electrons, the weights of some isotopes can be significantly more or less than the weight of the general element. Such isotopes occur more more rarely than the general element. If you were to plot the weights of the element and its isotopes, the isotopes could be clearly identified as falling far away from the accepted mean. The best work to describe the isotopes as they relate to such a plot in statistics would be:
- Aoutlier
- Bresidual
- Cdeviation
- Dquartile
- Eminimum
39The 23 members of the math club decide to hold the "random awards" in which they use a random number table to award 1st, 2nd, and 3rd place prizes. Each member is given a two-digit number from 01 to 23, then the prizes are drawn in reverse order with 3rd prize being the first member who appears in the random number table below when the digits are read two at a time:
92646 90110 79365 04891 39174 39823
Which numbered members of the math club won the three prizes?- A11, 04, 17
- B9, 2, 6
- C01, 10, 17
- D01, 11, 10
- E23, 17, 10
40Sales of jelly (X) and sales of peanut butter (Y) at a local store are recorded weekly. The correlation between X and Y is 0.9. Which is the best explanation of what this correlation means?
- A90% of customers either buy peanut butter or jelly.
- B90% of the time when a customer buys peanut butter, they also buy the jelly.
- C90% of the variability in peanut butter sales can be explained by variability in jelly sales.
- D81% of the variability in peanut butter sales can be explained by the variability in jelly sales.
- E90% of the time when the price of peanut butter goes up, so does the price of jelly.
Información
- Descripción
- Practice test for the AP Statistics Exam. This exam is timed (1 hr. 30 minutes) and contains 40 questions.
- Autor
- kobayashistats
- Idioma
- English
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