Answer:
1. 68%
2. 50%
3. 15/100
Step-by-step explanation:
Here, we want to use the empirical rule
1. % waiting between 15 and 25 minutes
From what we have in the question;
15 is 1 SD below the mean
25 is 1 SD above the mean
So practically, we want to calculate the percentage between;
1 SD below and above the mean
According to the empirical rule;
1 SD above the mean we have 34%
1 SD below, we have 34%
So between 1 SD below and above, we have
34 + 34 = 68%
2. Percentage above the mean
Mathematically, the percentage above the mean according to the empirical rule for the normal distribution is 50%
3. Probability that someone waits less than 5 minutes
Less than 5 minutes is 3 SD below the mean
That is 0.15% according to the empirical rule and the probability is 15/100
