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1. Discuss the advantages and disadvantages of range and
standard deviation as measures of variability of the scores.
2. a. Calculate the z score for a score of 5 in a
distribution with a mean of 7 and a standard deviation of 0.5.
b. What would the stanine score for this score be?

Using Table A.1, what is the estimated percentile rank for a z score of +1.20?
Table A.1

1. Why do you think the U.S. Census Bureau reports median
income instead of mean income?
2. On an analysis of achievement test, male
scores were more heterogeneous, more
spread from low to high, than female
scores.
a. Which statistics would be greater for
males?
b. Which gender had more stanine scores
of 9?
c. Which gender had more stanine scores
of 1?
d. Which gender had more stanine scores
of 5?

The mean score on a test is 40, and the
standard deviation is 4. Express each of the
following raw scores as a z score:
a. 41
b. 30
c. 48
d. 36
e. 46

a. What would be the T score for the raw score of 46 in
Exercise 12?
b. What would the stanine score for the raw score of 46 be?
Exercise 12
The mean score on a test is 40, and the
standard deviation is 4. Express each of the
following raw scores as a z score:
a. 41
b. 30
c. 48
d. 36
e. 46

1. In a normal distribution, what percentage of the scores
would fall below a z score of −1.0? A z score of 0? A z score of +.67?
2. Each dot in a scatterplot represents _____.

Describe the relationship shown by these scatterplots. Then
estimate the correlation coeffi cients.

Five girls took a history test and a geography test, with
the following results:
a. What is the mean of the history test?
b. Whose performance in history is most in agreement with
her performance in geography?
c. What is the correlation between the history and geography
scores?

Given that the history test mean in Exercise
17 is lower than the geography test mean,
which of the following conclusions would
be correct?
a. These girls are better in history than in
geography.
b. These girls are better in geography than
in history.
c. Their teacher has probably spent twice
as much time on geography as on history.
d. Their teacher knows more geography
than history.
e. None of the above

If the coeffi cient of correlation between
variable X and variable Y is found to be
−.98, which of the following would be
indicated?
a. Variable X and variable Y are closely
related.
b. Variable X and variable Y are unrelated.
c. Variable X and variable Y are perfectly
related.
d. Variable Y is a result of variable X.