# Discretionary music purchases are a big business. Albums can be downloaded, streamed, played from a CD, played on vinyl, and more. What types of albums are being purchased in the United States? Music albums can be classified as current or catalog albums. The difference between the two is that a catalog album is at least 18 months old. Questions 6

Discretionary music purchases are a big business. Albums can be downloaded, streamed, played from a CD, played on vinyl, and more. What types of albums are being purchased in the United States? Music albums can be classified as current or catalog albums. The difference between the two is that a catalog album is at least 18 months old. Questions 6 and 7 focus on data comparing album unit sales in the millions in both categories over a period of 7 years, as illustrated in this chart:

a. Construct a scatter plot using the year number as the x-coordinate and current album sales as the y-coordinate. Use 0 ≤ x ≤ 8 as the x-axis interval and 100 ≤ y ≤ 220 as the y-axis interval.

b. Use the scatter plot points to find the equation of the linear regression line for the current album sales. Round the slope and the y-intercept to the nearest hundredth.

c. What is the slope of the linear regression line?

d. What are the units of the slope when it is expressed as a rate?

e. Based on the linear regression line, how many millions of current albums would you expect in 2016? Round to the nearest tenth of a million.

f. Is your answer to part d interpolation or extrapolation? Explain.

g. Find the correlation coefficient to the nearest hundredth.

h. Describe the correlation.

**Related Book For**

## Financial Algebra Advanced Algebra With Financial Applications

2nd Edition

Authors: Robert Gerver, Richard J. Sgroi

ISBN: 9781337271790