HELP! an electrician charges $40 to make a trip to a job site. she charges an additional $50 per hour for three hours or less. if the job takes over three hours, she charges $60 per hour and doesn't charge for the trip. describe the function (write an equation) for each scenario and give the domain and range of each.

Thompson and thompson is a steel bolts manufacturing company. their current steel bolts have a mean diameter of 127 millimeters, and a variance of 36. if a random sample of 35 steel bolts is selected, what is the probability that the sample mean would differ from the population mean by greater than 0.5 millimeters? round your answer to four decimal places.