SOLUTION: I have been working on my homework all day and this may be the simplest of problems but I am confusing myself and I was wondering if I could get a little help figuring it out. Can

Algebra ->  Probability-and-statistics -> SOLUTION: I have been working on my homework all day and this may be the simplest of problems but I am confusing myself and I was wondering if I could get a little help figuring it out. Can       Log On


   



Question 314741: I have been working on my homework all day and this may be the simplest of problems but I am confusing myself and I was wondering if I could get a little help figuring it out. Can you show me how you get the answer.
Suppose on a highway with a speed limit of 65 mph, the speed of cars are independent and normally distributed with an average speed = 65 mph and standard deviation = 5 mph. What is the expected value of the sample mean speed in a random sample of n = 100 cars?
A) 13 mph
B) 0.65 mph
C) 6.5 mph
D) 65 mph
Thanks,
Dave

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Suppose on a highway with a speed limit of 65 mph, the speed of cars are independent and normally distributed with an average speed = 65 mph and standard deviation = 5 mph.
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What is the expected value of the sample mean speed in a random sample of
n = 100 cars?
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The distribution of ALL samples of size
100 has a mean of 65 and std=5/sqrt(100).
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Expected value of the sample mean speed = 65 mph.
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Cheers,
Stan H.
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A) 13 mph
B) 0.65 mph
C) 6.5 mph
D) 65 mph