23. Consider the following frequency distribution of weights of 150 bolts: Weight (grams) Frequency 5.00 and less than 5.01 4 5.01 and less than 5.02 18 5.02 and less than 5.03 25 5.03 and less than 5.04 36 5.04 and less than 5.05 30 5.05 and less than 5.06 22 5.06 and less than 5.07 11 5.07 and less than 5.08 3 5.08 and less than 5.09 1 (a) (b) (c) Calculate the mean and standard deviation of the weights of bolts to three decimal places. Estimate from the frequency distribution, the number of bolts which are within one standard deviation of the mean. Suppose that each bolt has a nut attached to it to make a nut-and-bolt. Nuts have a distribution of weights with a mean of 2.043 grams and standard deviation 0.008. Calculate the standard deviation of the weights of nut-and- bolts.