Test
B - Stat
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Preguntas del test (50)
1The main purpose of descriptive statistics is to
- ASummarize data in a useful and informative manner
- BMake inferences about a population
- CDetermine if the data adequately represents the population
- DBoth A and C are major purposes of descriptive statistics
- EAll of the above
2What type of variable is shoe size for male shoes?
- AInterval
- BContinuous
- COrdinal
- DDiscrete
- ENone of the above
3A survey includes a question regarding marital status that has the following responses: single, married, divorced, separated, or widowed. What is the scale of measurement for this question?
- AQualitative
- BRatio
- CNominal
- DOrdinal
- EContinuous
4Number of Wins for college football teams is what level of measurement?
- ADiscrete
- BOrdinal
- CInterval
- DRatio
- EContinuous
5What type of variable is monthly inches of rainfall?
- AInterval
- BOrdinal
- CContinuous
- DDiscrete
- ENone of the above
6For an ordered data set with some variation in the data and an even number of observations, half of the observations will be greater than the
- AMedian
- BMode
- CMean
- DAll of the above
- ENone of the above
7For data that have been ordered from smallest to largest values, where is the median located?
- An
- Bn/2
- C(n+1)/2
- Dn + 3/z
- En + 2
8A sample of paramedical fees charged by clinics revealed these amounts: $55, $49, $52, and $55. What is the median charge?
- A$47.5
- B$50
- C$52
- D$49
- ENone of the above
9Which measures of central location are not affected by extremely small or extremely large values?
- AMean and median
- Bmean and mode
- Cmode and median
- Dmean, median, and mode
- EAll measures
10The mode, as a measure of central location would be inappropriate for which of the following?
- AAges of adults as a senior citizen center
- BWeights of people residing in the state of Georgia
- CNumber of pages in textbooks on statistics
- DMarital Status of college students at a particular university
- EIt would be appropriate for all of the above
11What level of measurement is needed in order to calculate the variance of a set of data?
- ADiscrete
- BOrdinal
- CInterval
- DRatio
- EContinuous
12The sum of the deviations from the mean is
- AThe z score
- Bequal to zero
- Cusually a large zero
- Dunkown
- Enone of the above
13What is the relationship between the variance and the standard deviance?
- AStandard deviation is the square root of the variance
- BStandard deviation is the square of the variance
- CStandard deviation is double the variance
- DStandard deviation is half of the deviance
- EThere is no relationship
14The number of hours per semester worked for a sample of students follows 139, 136, 131, 136, 147, 130, 135, 138, 139 and 142. What is the range?
- A10
- B136 to 139
- C130 to 147
- D17
- ENone of the above
15The number of hours per semester worked for a sample of students follows 139, 136, 131, 136, 147, 130, 135, 138, 139 and 142. What is the mode?
- A136
- B139
- C136 and 139
- D130, 136, and 139
- Enone of the above
16What is the variance for a sample of hourly wages, if the standard deviation was computed to be $5?
- A$25
- B$5
- C$50
- DIt is equal to the square root of $5
- ECannot be determined
17Which of the following is correct about a probability distribution?
- AA. the sum of the population of all possible outcomes must equal 1.0
- BB. The outcomes must. be mutually exclusive
- CC. the probability of each outcome must be between 0 & 1 inclusive
- DD. All of the Above
- EE. A & C
18The time needed to complete an exam is
- AA continuous random variable
- BA discrete random variable
- CInterval data
- DOrdinal data
- ENone of the above
19For a normal distribution, the mean plus and minus 1 standard deviation will include about what percent of the observations?
- A50%
- B99.7%
- C95%
- D68%
- EAll of the observations
20What is the area under the normal curve between z = .44 and z = 2 ?
- A.4712
- B.6422
- C.1703
- D.4400
- E.3072
21For a standard normal distribution, what is the probability that z is greater than -0.44?
- A-.1700
- B-.3300
- C.6700
- D.1700
- E.5600
22A new extended-life light bulb has an average life of 750 hours, with a standard deviation of 50 hours. If the life of these light bulbs approximates a normal distribution, about what percent of the distribution will be between 600 hours and 900 hours?
- A95%
- B68%
- C99.7%
- DCannot be Determined
23Two normal distributions are compared. One has a mean of 10 and a standard deviation of 10. The second normal distribution has a mean of 10 and a standard deviation of 20. Which of the following is true?
- AThe locations of the distributions are different
- BThe distributions are from two different families of distributions
- Cthe shapes of the distributions are different
- DAll of the above
- ENone of the above
24A z value is
- AA measure of distance
- BA measure of probability
- CA measure of central location
- DA measure of skewness
- EA measure of both probability and of central location
25A random variable with outcomes that follow a normal distribution
- AWill have an infinite number of possible outcomes
- BWill have a discrete number of possible outcomes
- CWill have a mean of 0 and a standard deviation of 1
- DWill have a mean of zero and can have any value for a standard deviation
- EBoth A and C above are correct
26Which of the following is NOT true in a normal distribution?
- AThe mean equals zero
- BThe mean is equal to the median
- CThe mean divides the distributions into two symmetric parts
- Dnone of the above
- Eall of the above
27To study the population of consumer perceptions of new technology, sampling the population is preferred over surveying the population because
- ASampling is more accurate
- BWe can compute z - scores
- Cit is quicker
- Dall of the above
- Enone of the above
28If we choose a random starting point and then select every fifth invoice in a file, what type of sampling is being employed?
- ASimple random sampling
- BSystematic sampling
- CStratified random sampling
- DCluster Sampling
- ENone of the above
29A population is divided into groups, and then elements from each of the groups are chosen for sampling. What type of sampling is used?
- ASimple random sampling
- BSystematic sampling
- CStratified random sampling
- DCluster sampling
- ENone of the above
30The difference between a population parameter and the sample statistic is
- AAt the center of a normal distribution
- BSampling error
- CUsually very large
- DUsually very small
- ENone of the above
31The expected value of the sampling distribution is
- Athe sample mean
- Bthe population mean
- Cthe sample statistic
- Dthe population parameter
- Enone of the above
32The standard error is
- Athe standard deviation of the sample
- Bthe standard deviation of the population
- Cthe standard deviation of the population distribution
- Dboth A and C are correct
- Enone of the above are correct
33A confidence interval is used to estimate
- Aa population parameter
- Ba sample mean
- Ca level of confidence
- Da sample statistic
- Eany of the above
34Which of the following would be used as a point estimate for the population parameter?
- Athe sample mean
- Bthe test statistic
- Cthe sample statistic
- Dthe population mean
- Ethe z value
35Mileage was recorded for a sample of 100 tires. The average tread life was 50,000 miles with a standard deviation of 3,500 miles. Which of the following provides the best estimate of the average tread life for the population of tires?
- A50,000
- B3,500
- C(50,000/100)
- D(3,500/100)
- Enone of the above
36Which of the statement(s) is/are correct about the t- distribution?
- Athe mean is zero
- Bthe shape is symmetric
- Cthe dispersion is based on degrees of freedom
- DA and B above are true
- EAll of the above are true
37How is the t-distribution similar to the z distribution ?
- ABoth are sampling distributions
- BBoth are families of distributions
- CBoth are continuous distributions
- DA and C are correct
- EAll of the above are correct
38A test to determine if the mean of the population is different from 40 resulted in a test statistic of 1.05. The sample size was 20. What is the p-value?
- Aless than .2
- Bgreater than .1
- Cgreater than .2
- Dless than .1
- Enone of the above
39Which of the following is true?
- AIf the results of a hypothesis test are statistically significant, they must also have practical significance
- BThe results of a hypothesis test can have statistical significance without having practical significance
- CThe results of a hypothesis test cannot have both statistical significance and practical significance
- Dnone of the above is true
40University officials say that a fee increase will be implemented if more than 75% of the voting student population supports the fee increase. If a sample of students reveals 95% confidence interval of [.76, .83], what conclusion can be drawn based on the interval?
- Aconclude that another sample is needed, because this one was not representative
- Bconclude it should not be implemented
- Cconclude it should be implemented
- Dthis interval does not allow any conclusion to be drawn
41If the confidence interval is too wide to be useful, what can be done to make it more precise?
- ADecrease the level of confidence
- BDecrease the sample size
- CIncrease the variability in the population
- DEither A or B.
- EAll of the above
42A null hypothesis makes a claim about a
- APopulation Parameter
- BSample Statistic
- CSample Mean
- Dz - value
- Eany of the above
43Using a .5 level of alpha for a one population test of a mean with a sample size of 25. What is the value from the table that will be used in the RR value for a two-tailed hypothesis test?
- A1.96
- B1.711
- C2.060
- D2.064
- Enone of the above
44What information is needed to find a p-value?
- Atype of test and alpha level
- Balpha level and test statistic
- Ctype of test and test statistic
- Dtype of test, alpha level, and test statistic
45What is a type 1 error?
- AAccepting a false null hypothesis
- BRejecting a false null hypothesis
- CAccepting a false alternate hypothesis
- DRejecting a false alternate hypothesis
- ERejecting a true null hypothesis
46if the alternate hypothesis states that (mu) does not equal 4,000, where is the rejection region for the hypothesis test?
- ACenter of the distribution
- BLower or left tail of the distribution
- CUpper or right tail of the distribution
- DBoth tails of the distribution
47What is the probability of making a type 1 error when the null hypothesis is actually false?
- A0
- B1
- CIt is alpha, which is usually .05
- Dit is unknown
- Enone of the above
48Based on the Nelsen ratings, the intel CB5 affiliate claims its 11:00 PM newscast reaches more than 36% of the viewing audience in the area. In a sample of 100 viewers, 41% indicated that they watch the late evening news on this local CBS station. Is the claim supported? To answer this question, the alternate hypothesis is:
- Api > .41
- Bpi = .41
- Cpi = .36
- Dpi > .36
- Enone of the above
49The power of hypothesis test is
- Aits ability to answer a question about a population parameter
- Bthe probability of rejecting the null hypothesis when the null is false
- Cthat we can make inferences about a sample mean
- Dnone of he above
- EA, B, and C are correct
50During hypothesis testing, the initial assumption about the null hypothesis is that
- Ait is false
- Bit is true
- Cit is unknown
- Dno assumption is made
Información
- Descripción
- Business/Economics Test sobre B - Stat, creado por Levi Whitlock el 24/02/2020.
- Autor
- Levi Whitlock
- Idioma
- English
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