Question 1 1 pts 

One item on a questionnaire asks, “How many siblings (brothers and sisters) did you have when you were a child?” A researcher computes the mean, the median, and the mode for a set of n = 50 responses to this question. Which of the following statements accurately describes the measures of central tendency?

Because the scores are all whole numbers, the mean will be a whole number.

 Because the scores are all whole numbers, the median will be a whole number.

 Because the scores are all whole numbers, the mode will be a whole number. 

 All of the other options are correct descriptions.

Question 2 1 pts 

The average (mean) verbal SAT score for the entire class of entering freshmen is 530. However, if you select a sample of 20 freshmen and compute their average verbal SAT score, you probably will not get exactly 530. What statistical concept is used to explain the commonly occurring difference that exists between a sample mean and the corresponding population mean?

statistical error 

sampling error 

effect size error

 parametric error

3.Question 3 1 pts

 The final step of hypothesis testing is to __________. Group of answer choices

 make a  decision to reject or retain the alternate hypothesis 

make a  decision to reject or retain the null hypothesis 

collect the sample data and compute the test statistic 

prove that the null hypothesis is false

Question 4

 1 pts For a population with its mean = 80 and its standard deviation  = 12, what is the z-score corresponding to X = 98? 

.5 

0 

1 

1.5

Question 5

 1 pts Probability values are always __________. 

greater than or equal to 0, but less than or equal to 1

 between -1.0 and +1.0

 between -1 and 0

 expressed in percentages, between 0% and 100%

Question 6 

For which of the following situations would a two-sample dependent t test most likely be employed?

comparing verbal skills for girls versus boys at age 5 years

 comparing self-esteem for junior high school students who participate in school athletics versus those who do not 

comparing problem-solving skills for biology majors versus art majors at UT Permian Basin

 comparing pain tolerance before and after taking a new pain medication 

Question 7 1

 pts In a hypothesis test, an extreme t-score value, like t = +3 or t = +4, __________. 

is probably in the critical region (or in the region of rejection

means that you should probably reject the null hypothesis 

is probably strong evidence of a statistically significant effect 

All of the above options are correct.

Question 8 1 pts The general manufacturer of the automobile each student drove was recorded by the statistics professor.  The resulting frequencies were:   Dodge = 8; Ford = 12; General Motors =  17; Toyota = 21;  Volvo = 4; and “other” = 14. If the resulting distribution of the number of times each auto type each student drove was represented with a graph, what kind of graph would be most  appropriate? Group of answer choices 

a histogram

 a polygon

 a histogram or a polygon 

a bar graph

Question 9 1 pts 

If a repeated-measures study shows a significant difference between two treatment means with  = .01, then you can __________. Group of answer choices 

reject the null hypothesis 

accept the null hypothesis

 retain the null hypothesis 

assert that the alternative hypothesis is false

Question 10 1 pts

 A Pearson correlation of r = -1.00 between X and Y indicates __________. Group of answer choices

 each time X increases, there is a perfectly predictable decrease in Y 

every change in X is related to a corresponding change in Y 

every decrease in Y is related to a corresponding  increase in X

 Each of the above three alternatives is correct with a correlation of -1.00.

Question 11 1 pts

How many individual scores are in the frequency distribution below?

X f 

5 1 

4 1 

3 4 

2 2

Group of answer choices 

N=5 

N=8

 N=16

 N=26

Question 12 1 pts In a study evaluating the effectiveness of a new medication designed to control high blood pressure, one sample of individuals is given the medicine and a second sample is given an inactive placebo. Blood pressure is measured for each individual. For this study, what is the dependent variable? Group of answer choices 

the medication 

the placebo 

blood pressure 

the individuals given the medication