Math Core

This test covers the data unit: measures of center and spread (including standard deviation and outliers), dot plots, histograms and box plots, two-way frequency tables, and correlation and causation.

Question 1

Find the mean of $6, \ 8, \ 9, \ 9, \ 12, \ 16$ .

Enter a number. Fractions like 3/4 and sqrt(2) are OK.

Question 2

Find the standard deviation $\sigma$ of $2, \ 4, \ 6, \ 8, \ 10$ . Round to the nearest hundredth.

Enter a number. Fractions like 3/4 and sqrt(2) are OK.

Question 3

A data set has $Q_1 = 12$ and $Q_3 = 20$ . Which of these values would be an outlier by the $1.5 \times \text{IQR}$ rule?

Question 4

How many outliers does this data set have, by the $1.5 \times \text{IQR}$ rule?

2, \ 14, \ 15, \ 16, \ 18, \ 19, \ 20, \ 21, \ 23, \ 35

Enter a number. Fractions like 3/4 and sqrt(2) are OK.

Question 5

A data set has a mean of $15$ and a standard deviation of $2$ . Every value is multiplied by $3$ . What are the new mean and standard deviation?

The box plot below is used in the next two problems.

Scores on a practice exam

Question 6

Look at the practice-exam box plot above. What is the interquartile range?

Enter a number. Fractions like 3/4 and sqrt(2) are OK.

Question 7

Look at the practice-exam box plot above. About what percent of the scores are above $40$ ?

Enter a number. Fractions like 3/4 and sqrt(2) are OK.

The histogram below is used in the next three problems.

Hours of volunteering last month (24 students)

Question 8

Look at the volunteering histogram above. What is the shape of the distribution?

Question 9

Look at the volunteering histogram above. How many students volunteered fewer than $4$ hours?

Enter a number. Fractions like 3/4 and sqrt(2) are OK.

Question 10

Look at the volunteering histogram above. Which measure of center best describes a typical number of hours, and how does the mean compare to it?

The two-way table below is used in the next two problems. It shows whether $140$ students have a part-time job.

	Has a job	No job	Total
Juniors	$18$	$42$	$60$
Seniors	$32$	$48$	$80$
Total	$50$	$90$	$140$

Question 11

Look at the job table above. What percent of the seniors have a job?

Enter a number. Fractions like 3/4 and sqrt(2) are OK.

Question 12

Look at the job table above. Of the students who have a job, what percent are juniors?

Enter a number. Fractions like 3/4 and sqrt(2) are OK.

Question 13

The correlation between the outdoor temperature and the amount of heating fuel a house uses each day is $r = -0.72$ . Which description is best?

Question 14

Among the elementary schools in a state, the number of students in a school who wear glasses is strongly correlated with the number of books in its library. Which conclusion is justified?