Can someone help me with this

What are the critical values that correspond to a 95% confidence level and a sample size of 93? a. 65.647, 118.136 b. 59.196, 128.299 c. 57.143, 106.629 d. 69.196, 113.145

Find the value of the cosine for angle a

The number of revolutions of two pulleys is inversely proportional to their diameters. if a 24-inch diameter pulley making 400 revolutions per minute is belted to an 8-inch diameter pulley, find the number of revolutions per minute of the smaller pulley.