Normal probability for unknown standard deviation
Now assume the distribution of SAT scores is normal with a mean of µ = 500 and standard deviation σ is unknown. If the mean SAT score is computed from a sample of n = 100 students from this population, and the standard deviation of those students' scores is s = 125.
A. What range of values should contain the sample mean 95% of time?
B. What range of values should contain the sample mean 99% of time?