Ch.6. "A carpet manufacturing company is comparing the tensile strengths of two different types of synthetic fiber. Synthetic fiber A used in manufacturing carpet has tensile strength that is normally...

Ch.6. "A carpet manufacturing company is comparing the tensile strengths of two different types of synthetic fiber. Synthetic fiber A used in manufacturing carpet has tensile strength that is normally distributed with mean 75 psi and standard deviation 8 psi, and synthetic fiber B has tensile strength that is 70 psi and standard deviation 12 psi. Random sample of nA = 16 and nB = 9 of fiber specimens are selected.

Find the probability that 3.5 < x̄a="" -="" x̄b=""><>

Determine the value of zs