Suppose a 99% confidence interval for μ turns out to be(1000,2100) If this interval was based on a sample of size n=26, explain what assumptions are necessary for this interval to be valid.
A) The population of salaries must have an approximate t distribution.
B) The sampling distribution of the sample mean must have a skewed distribution.
C) The sampling distribution must be biased .
D) The population must have an approximately normal distribution.