Skewed distribution with mean of 30min and stardard dev. of 6min

[Eldridge Serrano]

The waiting times for patients at a walk-in clinic have a skewed distribution with mean of 30 minutes and standard deviation of 6 minutes.

1)Find the minimum percentage of patients at this walk-in clinic who will have to wait for:
i. 15 to 45 minutes

2)Find the interval that contains waiting times of at least 75% of the patients.

 

[afos]

The information given in the formulation above is insufficient. You must have been told something extra about the problem. So far there is a continuum of distributions that fit the description.