A. Z = (score-mean)/SD
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability of the Z score. Multiply by 100.
B. Use same table to find Z for P = .01. Insert in above equation and calculate.
C. Process same as A, but don't multiply by 100.
A company that produces rivets used by commercial aircraft manufactures knows that the shearing strength (force required to breaking) of its rivets is a major concern. The company believes the shearing strength of its rivets is normally distributed with a mean of 925 lbs and a standard deviation of 18 lbs.
A. If the company is correct, what percentage of its rivets have a shearing strength greater than 900 lbs?
B. What is the upper bound for the shearing strength of the weakest 1% of its rivets?
C. If one rivet is randomly selected from all of the rivets, what is the probability that it will require a force of at least 920 lbs to break it?
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