A research analyst believes that a positive relationship exists between a firm's advertising expenditures and its sales.For 65 firms,she collects data on each firm's yearly advertising expenditures and its sales.She calculates a Spearman rank correlation coefficient of 0.45.At the 5% confidence level,which of the following is the correct conclusion about the relationship between advertising and sales? _________
A) Reject the null hypothesis;we cannot conclude that the advertising and sales are related.
B) Do not reject the null hypothesis;conclude that the advertising and sales are related.
C) Reject the null hypothesis;conclude that the advertising and sales are related.
D) Do not reject the null hypothesis;we cannot conclude that the advertising and sales are related.

Question

Quizplus · Accepted Answer

The calculated Spearman rank correlation coefficient of 0.45 indicates a positive relationship between advertising expenditures and sales. At 5% confidence level, we would reject the null hypothesis if the calculated correlation coefficient is greater than or equal to 0.348. Because 0.45 is greater than 0.348, we reject the null hypothesis and conclude that the advertising and sales are related. Hence, the correct answer is choice C.

A Research Analyst Believes That a Positive Relationship Exists Between