Study Guide for Exam 1

Disclaimer: This short study guide is intended for extra practice. I may pull questions that are

based from lecture, homework, quizzes, or other places. (for example, know how to estimate

the standard deviation, know how to classify data with level of measurement).

1. Thirty-six workers were randomly surveyed about how long it takes themj to travel to

work each day. The data below are given minutes.

20 45 42 52 65 20 60 49 24 37 23 24 50 59 62 45 52 61

41 25 28 27 50 47 58 40 42 48 40 45 39 55 50 55 48 60

a. Find the . Round your answer to one decimal place.

b. Find the mode.

c. Find the range

d. Construct a stemplot

Stem (tens) Leaf (units)

e. Find the 68% interval according to the empirical rule.

g. Find the usual range, according to the empirical rule.

h. Find the class width if we wish to make a frequency distribution table with 3 classes.

Complete the frequency distribution table below:

Class

Boundaries

Class

Midpoint

Class

Frequency

Cumulative

Frequency

Relative

Frequency

Percentage

Frequency

2. Jess took an exam where the class average/mean was 84 points. Jess had earned 62 points. The standard

deviation of the class scores was 12 points. Find the z score for Jess' score. Was their score usual or unsual?

3. With the class average of 74points and standard deviation of 12 points. What percentage of the scores should fall between 50 points and 98 points?