Ms. Cook's class bought 2 bags of concrete and some bricks to build a border for their class garden. The bricks cost
$51. The total cost of the bricks and the concrete was $57.
Which equations can be used to find the cost, b, of 1 bag of
concrete?
o 2(51) + b = 57
o 2b + 51 = 57
O 2 + 51b = 57
ob + 51 = 57

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.