A company is interested in understanding the relationship between advertising expenditure and sales revenue. The company collected
Question:
A company is interested in understanding the relationship between advertising expenditure and sales revenue. The company collected data on advertising expenditure (in thousands of dollars) and sales revenue (in millions of dollars) for 10 randomly selected stores. The data is provided in the table below:
Store | Advertising Expenditure (x) | Sales Revenue (y) |
---|---|---|
1 | 20 | 3.6 |
2 | 15 | 2.9 |
3 | 10 | 2.2 |
4 | 18 | 3.5 |
5 | 12 | 2.6 |
6 | 25 | 4.2 |
7 | 8 | 1.9 |
8 | 16 | 3.0 |
9 | 22 | 3.9 |
10 | 14 | 2.7 |
a) Calculate the sample correlation coefficient between advertising expenditure and sales revenue.
b) Determine if there is a significant linear relationship between advertising expenditure and sales revenue at a 5% significance level.
c) Calculate the slope and intercept of the regression line for predicting sales revenue from advertising expenditure.
d) Use the regression line to predict the sales revenue for a store that has an advertising expenditure of $19,000.
e) Calculate the coefficient of determination and interpret its meaning.
Statistics The Exploration & Analysis Of Data
ISBN: 9780840058010
7th Edition
Authors: Roxy Peck, Jay L. Devore