Suppose the heights of adult men are normally distributed. The heights of a sample of 30 men are shown below, in inches. 65, 83, 69, 67, 69, 67, 67, 72, 85, 68, 73, 65, 67 ,65, 72, 71, 67, 73, 68, 72, 61, 75, 66, 78, 65, 71, 68, 76, 67, 68. What is the mean and standard deviation of this sample? a. mean: 70 standard deviation: 4.626 c. mean: 70 standard deviation: 5.228 b. mean: 67 standard deviation: 4.626 d. mean: 67 standard deviation: 5.228