Which expression is equivalent to 63.56+(-81.47)? A.63.56-81.47
B.63.56+81.47
C.-63.-81.47
D.-63.56+81.47

If 20% of a number is 35, what is 50% of that number?

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.

The two square pyramids are similar. find the total volume of both pyramids if the ratio of their surface areas is 9/16