An article in human factors (june 1989) presented data on visual accommodation (a function of eye movement) when recognizing a speckle pattern on a high-resolution crt screen. the data are as follows: 36.45, 67.90, 38.77, 42.18, 26.72, 50.77, 39.0, and 51.47. calculate the sample mean and sample standard deviation. round your answers to 2 decimal places. sample mean