A company wants to estimate the average sales lunch expense. They want to be within $5 of the true mean when using a confidence interval of 95%. The standard deviation is estimated at $25.
How many lunch receipts must they sample?
(Remember when calculating a sample size, we need to round UP to the next whole number, not the closest whole number if needed)
If less than that many receipts are sampled, which answer best describes what happens?
A) The error is more than the desired error of $5
B) The error is less than the desired error of $5
C) The level of confidence must be increased
D) The confidence interval must be widened
E) The standard deviation is not accurately estimated