2. A pub offers a '10 oz Steak Special'. If the steaks they use for these meals have uncooked weights that are normally distributed with a mean of 9.8 ounces and a standard deviation of 0.5 ounces, what is the probability that a customer will get:

Question

I) A steak that has an uncooked weight of more than 10 ounces?
II) A steak that has an uncooked weight of more than 9.5 ounces?
III) A steak that has an uncooked weight of less than 10.5 ounces?
IV) In the population of uncooked steaks, what is:
a) The minimum weight of the heaviest 20% of the steaks?
b) The maximum weight of the lightest 10% of the steaks?
V) A group of four friends visit the pub and each of them orders a 'Steak Special'. What is the probability that the mean uncooked weight of the steaks they order is more than 10 ounces?

Answer 1

Z = (score-mean)/SD

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportions related to the Z scores.

For V, use Z = (score-mean)/SEm

SEm = SD/√n