Customers experiencing technical difficulty with their Internet cable service may call an 800 number for technlcal support. it takes the technician between 90 seconds and 13 minutes to resolve the problem. The distribution of this support time follows the uniform distribution. a. What are the values for a and b in minutes? (Do not round your intermediate calculations, Round your answers to 1 decimal place.) b-1. What is the mean time to resolve the problem? (Do not round your intermediate calculations. Round your answer to 2 decimal places.) b-2. What is the standard deviation of the time? (Do not round your intermediate calculations. Round your answer to 2 decimal ploces.) c. What percent of the problems take more than 5 minutes to resolve? (Do not round your intermediate calculations. Round your answer to 2 decimal places.) d. Suppose we wish to find the middle 50% of the problem-solving times. What are the end points of these two times? (Do not round your intermediate calculations. Round your answers to 3 decimal places.)