Question 3

(a) A sample of 25 tests was taken to determine the compression strength of concrete.

The test results are:

27 28 34 37 35 41 36 45 34 42 34 42 34

32 51 29 38 25 34 33 66 39 37 39 35

Analyze and compute the following sample descriptive statistics:

mean, median, mode, range, standard deviation, variance, lower quartile,

upper quartile, interquartile range, 80th percentile, coefficient of variation

(b) Suppose one particular shipment of washing machines is accepted upon delivery

if a functional test of ten randomly selected washing machines yields no more

than one defective washing machine. Analyze and compute the probability that

this shipment is not accepted if 20 % of the shipment is defective.