The average time taken for your Internet service provider to remotely resolve a trouble ticket has a Normal distribution, with a mean of XXXXXXXXXXhours and a standard deviation of XXXXXXXXXXhours....

The average time taken for your Internet service provider to remotely resolve a trouble ticket has a Normal distribution, with a mean of 4.3 4.3 hours and a standard deviation of 3.1 3.1 hours. What percentage of the tickets are resolved in less than half an hour