For a Sample of 200 Laboratory Rats, the Mean Time

Short Answer

For a sample of 200 laboratory rats, the mean time to traverse a special experimental maze on the first trial was 22.5 seconds with a standard deviation of 4.7 seconds. Use the normal curve model to estimate the value(s):
(a)below which the 20 shortest time scores fell;
(b)above which the 50 longest time scores fell;
(c)below which the 130 shortest time scores fell;
(d)between which the central 140 time scores fell