Question 1

Which of the following is not a major stage of data analysis?

Accepted Answer

A) getting to know the data 
B) transforming the data 
C) confirming what the data reveal 
D) summarizing the data

Question 2

When interpreting confidence intervals when there are three or more means,if the intervals do not overlap,we have evidence that

Accepted Answer

A) the differences among population means are inconclusive. 
B) the sample means do not differ. 
C) the range of values for each interval is extreme. 
D) the population means differ.

Question 3

Distributions of scores for two groups in an experiment can be compared by

Accepted Answer

A) arranging a stem-and-leaf display for each group side-by-side. 
B) preparing one stem-and-leaf display using the scores for both groups. 
C) arranging the "stems" for both groups in one stem-and-leaf display and the "leaves" for both groups in a second stem-and-leaf display. 
D) none of these

Question 4

A score that is extreme and does not "go with" other scores in the distribution is called an

Accepted Answer

A) outlier. 
B) impossible value. 
C) significant value. 
D) error.

Question 5

A stem-and-leaf display is something like a ___________ on its side.

Accepted Answer

A) frequency polygon 
B) bimodal distribution 
C) histogram 
D) normal distribution

Question 6

The mean of a random sample of scores is a point estimate of

Accepted Answer

A) the population mean. 
B) the center of a distribution. 
C) standard error of the mean. 
D) population variability.

Question 7

A conceptual definition of effect size is the difference between two sample means for independent variable conditions,divided by

Accepted Answer

A) the variability within the groups. 
B) the sample size,N. 
C) Cohen's d. 
D) the population difference between two means.

Question 8

One reason we may not make causal conclusions based only on correlational evidence is that a correlation between two variables

Accepted Answer

A) may be zero. 
B) may be negative. 
C) does not tell us about the possible direction of causality. 
D) never involves causally related variables.

Question 9

If a stem-and-leaf display were created for the following set of numbers,23,24,24,21,20,27,29,28,we would expect the digit 2 to be a

Accepted Answer

A) stem. 
B) leaf. 
C) tree. 
D) trunk.

Question 10

Having calculated a 95% confidence interval for a difference between two means,we may conclude that the odds are 95/100 that the

Accepted Answer

A) true population mean difference falls in the interval. 
B) difference between the sample mean is the same as the difference between the population means. 
C) obtained interval contains the true population mean difference. 
D) population mean difference is less than 95.

Question 11

When two variables are correlated,our ability to make ___________ increases.

Accepted Answer

A) causal inferences for these variables 
B) predictions for these variables 
C) predictions about a third variable 
D) causal inferences about a third variable

Question 12

If a scatterplot shows that most of the points fall on a straight line,we can be confident that the correlation between the two measures is

Accepted Answer

A) weak. 
B) strong. 
C) unable to be determined. 
D) zero.

Question 13

The direction (positive or negative)of a correlation is indicated by

Accepted Answer

A) the absolute value of the correlation. 
B) numbers between 0.0 and 1.00. 
C) the sign of the coefficient. 
D) our ability to make predictions for the variables.

Question 14

What are two factors that affect the width of a confidence interval?

Accepted Answer

The answer of What are two factors that affect the...

Question 15

Which of the following procedures would not be expected during the first stage of data analysis?

Accepted Answer

A) checking for errors 
B) looking for outliers 
C) performing tests using inferential statistics 
D) visualizing the distribution with graphical displays

Question 16

The "margin of error" provides a range of values that are likely to contain the

Accepted Answer

A) sample mean. 
B) sample standard deviation. 
C) effect size. 
D) population mean.

Question 17

Describe the advantages and disadvantages of the three measures of central tendency: mean,median,mode.

Accepted Answer

The answer of Describe the advantages and disadvantages of the...

Question 18

It was suggested in the textbook that the correlation between measures of intelligence and mental illness is close to

Accepted Answer

A) 0.00 
B) -.50 
C) +.50 
D) +1.00

Question 19

The estimated standard error of the mean is equal to the sample ______ divided by _______.

Accepted Answer

A) variance;N 
B) standard deviation;  N 
C) standard deviation: N 
D) standard deviation;N -1

Question 20

The most commonly used measure of central tendency is the

Accepted Answer

A) range. 
B) mean. 
C) median. 
D) mode.

Exam 11: Data Analysis and Interpretation: Part I Describing Data,confi Dence Intervals, Correlation