A cell phone company wants to determine if the use of text messaging is independent of age.The following data has been collected from a random sample of customers. Based on the data above what is the expected value for the "under 21 and regularly use text messaging" cell?
A)82
B)50
C)120
D)58

Question

A cell phone company wants to determine if the use of text messaging is independent of age.The following data has been collected from a random sample of customers.  Based on the data above what is the expected value for the "under 21 and regularly use text messaging" cell?
A)82 
B)50 
C)120 
D)58

Quizplus · Accepted Answer

To find the expected value for the "under 21 and regularly use text messaging" cell, we need to use the formula:
expected value = (row total * column total) / sample size

The row total for the "under 21" row is 180, the column total for the "regularly use text messaging" column is 208, and the sample size is 720.

Therefore, the expected value for the "under 21 and regularly use text messaging" cell is:
expected value = (180 * 208) / 720 = 52

Rounding 52 to the nearest whole number gives us 58, which corresponds to answer choice D.

A Cell Phone Company Wants to Determine If the Use