Get the Z score and then you can answer the questions?
Visitors to the zoo an average of 74 minutes. This is normally distributed with a standard deviation of 23 minutes. If appropriate, calculate... a. What percent of visitors spend more than 30 minutes at the zoo?
What is the upper cutoff for time where only 5% of people spend LONGER at the zoo than that time?
What is the lower cutoff for time where only 5% of people spend LESS TIME at the zoo than that amount?
The zoo closes at 6pm. If you stop letting people in at 5pm, what percent of those visitors would still be enjoying the zoo at closing time?