7.2.21 Statistics Rule of Thumb// HELP PLEASE/ Explain please

Question

Assume that all grade-point averages are to be standardized on a scale between 0 and 4. How many grade-point averages must be obtained so that the sample mean is within 0.011 of the population mean? Assume that 99% confidence level is desired. If using the range rule of thumb, σ can be estimated as

range/4=4-0/4=1 Does the sample size seem practical?

Answer 1

n = (z alpha/2 * S/E)^2

where n = sample size, z alpha/2 = critical value for 99% confidence = 2.58, S = 1 and E = 0.011.

n = (2.58 * 1 / 0.011)^2 = 55011.57 ~ 55012

Sample size does not seem practical.