Amarketing research company needs to estimate the average total compensation of ceos in the service industry. data were randomly collected from 18 ceos and the 98% confidence interval was calculated to be ($2,181,260, $5,836,180). what assumptions are necessary for this confidence interval to be valid?
a) the distribution of the means is approximately normal
b) the total compensation of ceos in the service industry is approximately normally distributed
c) the sample is randomly selected from a population of total compensations that is a t distribution
d) none. the central limit theorem applies.