A store manager wishes to investigate whether there is a relationship between the type of promotion offered and the number of customers who spend more than $30 on a purchase. Data will be gathered and placed into the two-way table below.

Question

Customer Spending by Promotion Run


Customers
Spending
More than $30
Customers
Spending
$30 or Less
$10 off $50

15% off

$5 off $25

Buy-1-Get-1 Half Off


Which statement best describes how the manager can check if there is an association between the two variables?
The manager must check relative frequencies by row because there are more than two different promotions.
The manager must check relative frequencies by column because there are more than two different promotions.
The manager cannot use relative frequencies to look for an association because there are more than two different promotions.
The manager should check both relative frequencies by row and by column to look for an association.

Answer 1

To investigate whether there is a relationship between the type of promotion offered and the number of customers who spend more than $30, the manager needs to analyze how the relative frequencies of spending more than $30 differ across the various promotions.

The best approach in this case is to check how the proportion of customers spending more than $30 varies by each type of promotion. Therefore, the manager should look at the relative frequencies by rows (i.e., comparing the proportion of customers spending more than $30 under each promotion).

Since there are multiple promotions (more than two), focusing on relative frequencies by row allows the manager to understand how the different promotions affect customer spending behavior.

Thus, the most accurate statement would be:

The manager must check relative frequencies by row because there are more than two different promotions.