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Statistics final exam
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Preguntas del test (46)
1which of the following are binomial experiments or can be reduced to binomial experiments?
- Asurveying 100 people to determine if they like sudsy soap
- Btossing a coin 100 times to see how many heads occur
- Cdrawing a card with replacement from a deck and getting a heart
- Dasking 1000 people which brand of cigarettes
- Etesting four different brands of aspirin to see which brands are effective
2the expected value of a random variable can be thought of as a long-run average
- AVerdadero
- BFalso
3the number of courses a student is taking this semester is an example of a continuous random variable
- AVerdadero
- BFalso
4when the binomial distribution is used, the outcomes must be dependent
- AVerdadero
- BFalso
5a binomial experiment has a fixed number of trials
- AVerdadero
- BFalso
6what is the sum of the probabilities of all outcomes in a probability distribution
- A0
- B1/2
- C1
- Dit cannot be determined
7how many outcomes are there in a binomial experiment
- A0
- B1
- C2
- Dit varies
8the number of trials for a binomial experiment
- Acan be infinite
- Bis unchanged
- Cis unlimited
- Dmust be fixed
9the total area under a normal distribution is infinite
- AVerdadero
- BFalso
10the standard normal distribution is a continuous distribution
- AVerdadero
- BFalso
11all variables that are approximately normally distributed can be transformed to standard normal variables
- AVerdadero
- BFalso
12the z value corresponding to a number below the mean is always negative
- AVerdadero
- BFalso
13the area under the standard normal distribution to the left of z=0 is negative
- AVerdadero
- BFalso
14the central limit theorem applies to means of samples selected from different populations
- AVerdadero
- BFalso
15the mean of the standard normal distribution is
- A0
- B1
- C100
- Dvariable
16approximately what percentage of normally distributed data values will fall within 1 standard deviation above or below the mean?
- A68%
- B95%
- C99.7%
- Dvariable
17which is not a property of the standard normal distribution?
- Ait's symmetric about the mean
- Bit's uniform
- Cit's bell shaped
- Dits unimodal
18when a distribution is positively skewed, the relationship of the mean, median, and mode from left to right will be?
- Amean, median, mode
- Bmode, median, mean
- Cmedian, mode, mean
- Dmean, mode, median
19the standard deviation of all possible sample means equals
- Athe population standard deviation
- Bthe population standard deviation divided by the population mean
- Cthe population standard deviation divided by the square root of the sample size
- Dthe square root of the population standard deviation
20Interval estimates are preferred over point estimates since the confidence level can be specified
- AVerdadero
- BFalso
21for a specific confidence interval, the larger the sample size, the smaller the margin of error will be.
- AVerdadero
- BFalso
22an estimator is consistent if as the sample size decreases, the value of the estimator approaches the value of the parameter estimated
- AVerdadero
- BFalso
23to determine the sample size needed to estimate a parameter, you must know the margin of error
- AVerdadero
- BFalso
24when a 99% confidence interval is calculated instead of a 95% confidence interval with n being the same, the margin of error will be
- Asmaller
- Blarger
- Cthe same
- Dit cannot be determined
25the best point of estimate of the population mean is
- Athe sample mean
- Bthe sample median
- Cthe sample mode
- Dthe sample midrange
26when the population standard deviation is unknown and the sample size is less than 30, what table value should be used in computing a confidence interval for a mean
- Az
- Bt
- Cchi-square
- Dnone of the above
27No error is committed when the null hypothesis is rejected when it is false
- AVerdadero
- BFalso
28when you are conducting the t test, the population must be approximately normally distributed
- AVerdadero
- BFalso
29the test value separates the critical region from the noncritical region
- AVerdadero
- BFalso
30the values of chi-square test cannot be negative
- AVerdadero
- BFalso
31the chi-square test for variance is always one tailed
- AVerdadero
- BFalso
32when the value of alpha is increased, the probability of committing a type 1 error is
- Adecreased
- Bincreased
- Cthe same
- Dnone of the above
33if you wish to test the claim that the mean of the population is 100, the appropriate null hypothesis is
- Ax(bar) = 100
- Bµ ≥ 100
- Cµ ≤ 100
- Dµ = 100
34the degrees of freedom for the chi-square test for variances or standard deviation are
- A1
- Bn
- Cn - 1
- Dnone of the above
35for the t test, one uses ________ instead of σ
- An
- Bs
- CX²
- Dt
36a negative relationship between two variables means that for the most part, as the x variable increases, the y variable decreases
- AVerdadero
- BFalso
37a correlation coefficient of -1 implies a perfect linear relationship between the variables
- AVerdadero
- BFalso
38even if the correlation coefficient is high (near +1) or low (near -1), it may not be significant
- AVerdadero
- BFalso
39when the correlation coefficient is significant, you can assume x causes y
- AVerdadero
- BFalso
40it is not possible to have a significant correlation by chance alone
- AVerdadero
- BFalso
41in multiple regression, there are several dependent variables and one independent variable
- AVerdadero
- BFalso
42the strength of the linear relationship between two quantitative variables is determined by the value of
- Ar
- Ba
- Cx
- Ds (subscript "est")
43to test the significance of r, a(n) ____ test is used.
- At
- BF
- CX²
- Dnone of the above
44the test of significance for r has _______ degrees of freedom.
- A1
- Bn
- Cn - 1
- Dn - 2
45the equation of the regression line used in statistics is
- Ax = a + by
- By = bx + a
- Cy' = a +bx
- Dx = ay + b
46the coefficient of determination is
- Ar
- Br²
- Ca
- Db
Información
- Descripción
- study guide for statistics final exam
- Autor
- Jess Todd
- Idioma
- English
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- 139
- Etiquetas
- Valoración
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