(a) The stiffness property of a new material is established by initial testing. The preliminary results show a uniform scatter of data in the range \(9 \mathrm{lb} /\) in \(\leq k \leq 11 \mathrm{lb} / \mathrm{in}\). There is no additional information. Calculate the mean value, standard deviation, coefficient of variation, and the probability that the stiffness is greater than \(9.5 \mathrm{lb} / \mathrm{in}\).

(b) The above spread of data is found to be too large, and so additional testing is carried out. A plot of the data shows the density in Figure 9.55. Calculate the same values as before and draw conclusions.

Transcribed Image Text:

2/3 1/3 0 -Stiffness Figure 9.55: Probability density of stiffness data.