a Calculate a point estimate of the mean value of strength f

(a) Calculate a point estimate of the mean value of strength for the conceptual population of all beams manufactured in this fashion. [Hint: sigma xi = 219.4.] (Round your answer to three decimal places.) State which estimator you used. (b) Calculate a point estimate of the strength value that separates the weakest 50% of all such beams from the strongest 50%. State which estimator you used. (c) Calculate a point estimate of the population standard deviation sigma. [Hint: sigma xi^2 = 1856.28.] (Round your answer to three decimal places.)

Solution

To find the value which seperates weakest 50% of beams to strongest 50% must lie in the middle, when these data points are arranged in ascending order.

The middle value is 7.7.

To calculate the standard deviation use the MS-EXCEL function STDEV and the standard deviation is found to be, 1.714.