4.3 The following 25 measurements were taken of the thickness of steel emerging from a rolling mill. 3.97 3.99 4.04 4.00 3.98 4.03 4.00 3.98 3.99 3.96 4.02 3.99 4.01 3.97 4.02 3.99 3.95 4.03 4.01 4.05 3.98 4.00 4.04 3.98 4.02 Find (a) the median, (b) the mean, (c) the standard deviation, and (d) the variance of the measurements. 4.14 By applying error function tables for the mean and standard deviation values calcu- lated in problem 4.3, estimate (a) How many measurements are <4.00? (b) How many measurements are <3.95? (c) How many measurements are between 3.98 and 4.02? Check your answers against the real data.