A Consumer Group Would Like to Estimate the Mean Monthly

Multiple Choice

A consumer group would like to estimate the mean monthly electricity charge for a single family
House in July (within $5) using a 99 percent level of confidence. Based on similar studies the
Standard deviation is estimated to be $20.00. How large a sample is required?

A) 105
B) 106
C) 107
D) 108
E) 109