$$79.10 + 2 \times 13.74 = 106.58$$

Question 1

Which of the following best describes the shape of the distribution in the third histogram (bell-shaped, centered at 8)?

Accepted Answer

Symmetric and bell-shaped distribution

Question 2

Given the bar chart of student classifications, what is the approximate relative frequency of students working on a second degree?

Accepted Answer

$$\frac{2}{29}$$

Question 3

A student scored 95 on exam2. Using the summary statistics (mean = 79.10, standard deviation = 13.74), what is the student's z-score?

Accepted Answer

$$z = \frac{95 - 79.10}{13.74} \approx 1.16$$

Question 4

Which exam (exam2 or exam4) has greater variability in scores? Use the standard deviation to justify your answer.

Accepted Answer

Exam4, because its standard deviation is higher.

Question 5

If a student scored at the 25th percentile on exam4, what was their score?

Accepted Answer

$$65$$

Question 6

Which of the following histograms best represents a uniform distribution?

Accepted Answer

The fourth histogram (all bars are the same height)

Question 7

In the histogram of exam2, what is the approximate mode of the exam scores?

Accepted Answer

Around 90

Question 8

Given the summary statistics for exam2, what is the interquartile range (IQR)?

Accepted Answer

$$IQR = Q_3$ - Q_1$ = 90 - 70 = 20$$

Question 9

A student scored 1100 on the SAT, where the mean is 1263 and the standard deviation is 114. What is the student's z-score?

Accepted Answer

$$z = \frac{1100 - 1263}{114} \approx -1.43$$

Question 10

Which of the following statements is true about the distribution of exam4 scores?

Accepted Answer

The distribution is right-skewed, as the mean is less than the median.

Question 11

If a student’s score on exam2 is 105, what percentile is this score closest to?

Accepted Answer

100th percentile

Question 12

In the histogram of the number of credit hours taken, how many students took between 60 and 80 credit hours?

Accepted Answer

5

Question 13

Which of the following best describes the distribution of the 'Height of students' histogram?

Accepted Answer

Left-skewed

Question 14

If the mean and median of a data set are equal, what can you infer about the shape of the distribution?

Accepted Answer

The distribution is likely symmetric.

Question 15

Given the summary statistics for exam4, what is the range of the exam scores?

Accepted Answer

$$Range = 105 - 30 = 75$$

Question 16

If a student scored 2 standard deviations above the mean on exam2, what was their score?

Accepted Answer

$$79.10 + 2 	imes 13.74 = 106.58$$

Question 17

Which of the following is NOT a measure of central tendency?

Accepted Answer

Standard deviation

Question 18

If the IQR for exam4 is 30, what does this value represent?

Accepted Answer

The range of the middle 50% of exam4 scores.

Question 19

If a student’s z-score is 0, what does this indicate about their score?

Accepted Answer

Their score is equal to the mean.

Describing and Summarizing Data: Tables, Graphs, and Numerical Measures

Study Guide - Practice Questions