Question 1

The use of the one-sample t test rests on the assumption that the sample.

Accepted Answer

A)  is symmetrical
B)  was randomly selected from the population
C)  variance is known
D)  standard deviation is known B

Question 2

The value 1 - β is the of a statistical test.

Accepted Answer

A)  Type II error potential
B)  power
C)  df
D)  Type I error potential B

Question 3

To enter a table of critical values of t, you must know.

Accepted Answer

A)  df for tobs
B)  tobs
C)  the value of X − μ
D)  the value of s A

Question 4

By setting alpha equal to .05, a "statistically rare" event is defined as an event occurring only 5 or fewer times in occasions if the hypothesis is true.

Accepted Answer

A)  1000; null
B)  100; null
C)  100; alternative
D)  1000; alternative

Question 5

When calculating s, the df are given by.

Accepted Answer

A)  N
B)  N + 1
C)  N - 1
D)  N - 2

Question 6

The power of a statistical test is given by.

Accepted Answer

A)   α\alphaα 
B)     1−α1-\alpha1−α 
C)    β\betaβ 
D)    1−β1 - \beta1−β

Question 7

If the result of a one-sample t test is reported as t(49) = 2.329, p < .05, then you know that.

Accepted Answer

A)  the critical value of t was 2.329
B)  the alpha level was less than .05
C)  the sample size was 49
D)  none of the above

Question 8

The test statistic z locates a sample mean on a distribution.

Accepted Answer

A)  positively skewed
B)  negatively skewed
C)  standard normal
D)  symmetrical and bimodal

Question 9

If the alternative hypothesis is true and H0 is not rejected, then.

Accepted Answer

A)  a Type I error has occurred
B)  a Type II error has occurred
C)  a correct decision has occurred
D)  it is possible that both a Type I and Type II error have occurred

Question 10

If the results of a study using the one-sample t test were summarized t(14) = 3.218, p < .01, then you would know that the probability of tobs if H0 is true is and that the difference between X and μ is.

Accepted Answer

A)  less than or equal to .01; nonsignificant
B)  less than or equal to.01; statistically significant
C)  greater than .01; nonsignificant
D)  greater than .01; statistically significant

Question 11

Suppose a non-directional z test was performed and the null hypothesis rejected with a significance level of .05. Which one of the following could have been the value of zobs in the statistical test?

Accepted Answer

A)  -1.98
B)  -1.68
C)  -1.34
D)  +1.68

Question 12

A statistically significant difference means that.

Accepted Answer

A)  the population mean is larger than the hypothesized sample value
B)  H0 was rejected and H1 accepted
C)  H0 was not rejected and H1 was not accepted
D)  the alpha level was lower than expected by chance alone

Question 13

For a parametric test a statistical hypothesis is a statement about.

Accepted Answer

A)  a characteristic of a sample
B)  the range of values in the population
C)  measures of central tendency for a sample
D)  a characteristic of a population

Question 14

If the result of a statistical test is reported as p < .05, then it indicates that the investigator .

Accepted Answer

A)  failed to reject H0
B)  failed to reject H1
C)  rejected H1
D)  rejected H0

Question 15

If H0 is true and it is not rejected, then has occurred.

Accepted Answer

A)  a Type I error
B)  a Type II error
C)  either a Type I or a Type II error
D)  a correct decision

Question 16

The theoretical sampling distribution of t varies with the.

Accepted Answer

A)  value of the sample mean
B)  range of values in the sample
C)  size of the sample
D)  value of the sample variance

Question 17

If zobs equals -.50 and zcrit equals plus or minus 1.96, then a statistical decision is to.

Accepted Answer

A)  reject the null hypothesis
B)  fail to reject the null hypothesis
C)  accept the alternative hypothesis
D)  fail to reject the alternative hypothesis

Question 18

A statistical test that locates rejection regions at both ends of the sampling distribution is called a test.

Accepted Answer

A)  one-tailed
B)  two-tailed
C)  unidirectional
D)  directional

Question 19

If tobs does not fall into a rejection region, then which of the following is true?

Accepted Answer

A)  The probability of obtaining the value of tobs under the null hypothesis is less than the alpha value.
B)  The alternative hypothesis is accepted.
C)  The null hypothesis is rejected.
D)  The null hypothesis is not rejected.

Question 20

Which of the following could be an appropriate alternative hypothesis for a statistical test concerning the mean income of 17-year old males?

Accepted Answer

A)    H1:Xˉ=$2617H _ { 1 } : \bar { X } = \$ 2617H1​:Xˉ=$2617 
B)    H1:μ=$2617H _ { 1 : } \mu = \$ 2617H1:​μ=$2617 
C)    H1:Xˉ≠$2617H _ { 1 } : \bar { X } 
eq \$ 2617H1​:Xˉ=$2617 
D)    H1:μ≠$2617H _ { 1 } : \mu 
eq \$ 2617H1​:μ=$2617

Exam 8: Is There Really a Difference Introduction to Statistical Hypothesis Testing