SOLUTION: In a random sample of 800 refreshment-dispensing machines, it is found that an average of 8.1 ounces is dispensed with a standard deviation of 0.85 ounce. Find the probability t

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Question 1036402: In a random sample of 800 refreshment-dispensing machines, it is found that an average of 8.1 ounces is dispensed with a standard deviation of 0.85 ounce.
Find the probability that the true mean is between 8.157 and 8.185. Round your answer to the tenths place.

Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
z(a)=(8.157-8.1)*sqrt(800)/0.85. Using z-value with sample size of 800. Dividing the denominator by the sample size is the same as multiplying it in the numerator.
z=1.89
z(b)=(8.185-8.1)*sqrt(800)/0.85
z=2.83
The probability is 2.7% (the distance between those two z-values.