Larry recorded his time as he ran. What was his average speed from hour 2 to hour 4?what was his average speed from hour 4 to hour 7? Did he speed up or slow down?

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.