Chattahoochee Battery Company has developed a new laptop computer battery. On average, the battery lasts 240 minutes on a single charge. The standard deviation is 16 minutes.

Suppose the company randomly samples production during each day at a specified time and selects 12 laptop batteries for testing. The standard deviation of the battery life for the selected batteries is 20 minutes. What is the chi-square statistic represented by this test?

²= [ ( n - 1 ) * s²] / ²

a) 14.232

b) 18.75

c) 17.188

d) 16.475