The Average Battery Life of the IPhone 4S Is Reported

Multiple Choice

The average battery life of the iPhone 4S is reported to be 7.0 hours. Assume that the standard deviation for the battery life for this cell phone is 45 minutes. A random sample of 38 iPhones had an average battery life of 6.5 hours. Which of the following statements is correct?

A) The interval that contains 95% of the sample means is 6.76 and 7.24 hours. Because the sample mean is not between these two values, we do not have support that the average battery life equals 7.0 hours.
B) The interval that contains 95% of the sample means is 6.76 and 7.24 hours. Because the sample
C) The interval that contains 95% of the sample means is 5.50 and 8.50 hours. Because the sample mean is between these two values, we have support that the average battery life equals 7.0 hours.
D) The interval that contains 95% of the sample means is 5.50 and 8.50 hours. Because the sample mean is between these two values, we do not have support that the average battery life equals 7.0 hours.