# Probability and normal distribution : key information

1. At a computer manufacturing company, the actual size of computer chips is normally distributed with a mean of 1 centimeter and a standard deviation of 0.1 centimeter. A random sample of 12 computer chips is taken. What is the standard error for the sample mean?

a) 0.029

b) 0.050

c) 0.091

d) 0.120

2. The owner of a fish market has an assistant who has determined that the weights of catfish are normally distributed, with mean of 3.2 pounds and standard deviation of 0.8 pound. If a sample of 25 fish yields a mean of 3.6 pounds, what is the Z-score for this observation?

a) 18.750

b) 2.500

c) 1.875

d) 0.750

3. The owner of a fish market has an assistant who has determined that the weights of catfish are normally distributed, with mean of 3.2 pounds and standard deviation of 0.8 pound. If a sample of 16 fish is taken, what would the standard error of the mean weight equal?

a) 0.003

b) 0.050

c) 0.200

d) 0.800

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#### Solution Summary

The solution solves the questions on probability and normal distributions.

Probability Using Normal Distribution: Key Information

The mean salary offered to students who are graduating from Coastal State University this year is $24,230, with a standard deviation of $3,712. A random sample of 80 Coastal State students graduating this year has been selected. What is the probability that the mean salary offer for these 80 students is 24,250 or less?

Carry your intermediate computations to at least four decimal places. Round your answer to at least three decimal places.

Can you explain this how to do this?

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