From the length(in seconds) of 80 randomly chosen U2 songs, the mean determined was 289.6986295 and standard deviation was 76.82292002. Assume that the data is normally distributed and that the bands entire collection of songs has a mean and standard deviation equal to those calculated above. What percentage of U2 songs are expected to be

Question

A.) over 180 seconds
B.) Between 210 seconds and 300 seconds
C.) Under what length of time will 90% of all U2 songs expected to be?

Answer 1

you can get a handle on this stuff at

http://davidmlane.com/hyperstat/z_table.html