Hi guys please help with my math, polo124 this is proof :)

Find the balance at the end of 4 years if 1000 is deposited at the rate of

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.

What is the best approximation for the area of a circle with a radius of 4 m ? use 3.14 to approximate pi