The following data reflect the number of customers who test drove new cars each day for a sample of 20 days at the Redfield Ford Dealership. Given these data,what is the variance?
A)0.69
B)Approximately 3.08
C)Approximately 9.52
D)Approximately 181

Question

The following data reflect the number of customers who test drove new cars each day for a sample of 20 days at the Redfield Ford Dealership.  Given these data,what is the variance?
A)0.69 
B)Approximately 3.08 
C)Approximately 9.52 
D)Approximately 181

Quizplus · Accepted Answer

To find the variance, we need to first find the mean, which is the sum of all the values (259) divided by the number of values (20), or 12.95. 
Then, we need to find the difference between each value and the mean, square each difference, and add up all the squared differences. This gives us 194.10. 
Finally, we divide the sum of squared differences by the number of values minus one (20 - 1 = 19) to get the variance, which is approximately 9.52.

The Following Data Reflect the Number of Customers Who Test