Back at Tinker Air Force Base, the specifications for a bolt used in an aircraft MRO application require that the ultimate tensile strength be at least 18 kN.
It is known that 10% of the bolts have strengths less than 18.3 kN and that 5% of the bolts have strengths greater than 19.76 kN.
Assume that the uncertain tensile strengths of bolts follow a normal distribution.
b. You pick five bolts out of a bin. What is the probability that at least four of them meet the strength specification?
