Question 447271: When a production process is operating correctly, the number of units produced per hour has a normal distribution with a mean of 100 and standard deviation of 10. A random sample of 4 hours was taken. Complete parts (a) through (d)
a. Find the mean of the sampling distribution of the sample means.
b. Find variance
c. Find standard error
d. What is the probability the sample mean exceeds 101.2?
thanks alot.. if you won't answer all, just parts of it will do because i need a guide to start the question, and then maybe i can just flow through.. :)
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! When a production process is operating correctly, the number of units produced per hour has a normal distribution with a mean of 100 and standard deviation of 10. A random sample of 4 hours was taken. Complete parts (a) through (d)
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a. Find the mean of the sampling distribution of the sample means.
mean of the sample means = 100
std of the sample means = 10/sqrt(4) = 5
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b. Find variance
var of the sample means = 5^2 = 25
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c. Find standard error
10/sqrt(2)
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d. What is the probability the sample mean exceeds 101.2?
t(101.2) = (101.2-100)/[10/sqrt(4)] = 1.2/5 = 0.24
P(x-bar > 101.2) = P(t > 0.24 when df = 3) = 0.4129
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Cheers,
Stan H.
thanks alot.. if you won't answer all, just parts of it will do because i need a guide to start the question, and then maybe i can just flow through.. :)
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