A medical laboratory tested 8 samples of human blood for acidity on the pH scale, with the results below: 7.4, 7.5, 7.6, 7.2, 7.5, 7.4, 7.1, 7.6.
a. Find the mean and standard deviation.
b. What percentage of the data is within 3 standard deviations of the mean?
a. The mean is 7.4125. The standard deviation is 0.1909.