Quiz #2 Answer all questions and upload to the Assignment Folder

1. Suppose that the correlation r between two quantitative variables was found to be r = 1. Which of the following is the best interpretation of this correlation value?

1. There is a strong linear relationship between the two variables.

2. There is no linear relationship between the two variables.

3. There is a strong relationship between the two variables.

4. There is no relationship between the two variables.

(Hint: You can review the OLI activities or do a computer search if in doubt)

2.Use the tables below to answer the questions that follow.

A. Which table tells us the percent of uninsureds for each region? What is that percent for the Northeast?

B. Which table tells us which region has the largest number of insureds for the country? Which region is that?

C. Which region has the most people? What percent of the country lives in this region?

3. A random sample of 25 customers was chosen in UMUC MiniMart between 3:00 and 4:00 PM on a Friday afternoon. The frequency distribution below shows the distribution for checkout time (in minutes).

Checkout Time (in minutes) Frequency Relative Frequency

1.0 – 1.9 2

2.0 – 2.9 8

3.0 – 3.9

4.0 – 5.9 5

Total 25

Complete the frequency table with frequency and relative frequency.

In what class interval must the median lie? Explain your answer

Assume that the largest observation in this dataset is 5.8. Suppose this observation were incorrectly recorded as 8.5 instead of 5.8. Will the mean increase, decrease, or remain the same? Will the median increase, decrease or remain the same? Why?

4. A random sample of STAT200 weekly study times in hours is as follows:

2 15 15 18 30

Find the sample standard deviation. (Round the answer to two decimal places. Show all work. Just the answer, without supporting work, will receive no credit.)

The boxplots below show the real estate values of single family homes in two neighboring cities, in thousands of dollars.

For each question, give your answer as one of the following: (a) Tinytown; (b) BigBurg; (c) Both cities have the same value requested; (d) It is impossible to tell using only the given information. Then explain your answer in each case. (5 pts each)

5. Which city has greater variability in real estate values?

6. Which city has the greater percentage of households with values $85,000 and over?

7. Which city has a greater percentage of homes with real estate values between $55,000 and $85,000?