SOLUTION: The average weight of 40 randomly selected minivans was 4150 pounds with a standard deviation of 480. Find a point estimate of the population mean. Find the 99% confidence interval

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Question 972972: The average weight of 40 randomly selected minivans was 4150 pounds with a standard deviation of 480. Find a point estimate of the population mean. Find the 99% confidence interval of the true mean weight of the minivans.
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
Point estimate is the sample mean, which is 4150 pounds. It is the best "guess" one has.
z.99=2.58
99% CI =+/-2.58 *SE of the mean.
SE= 480/sqrt (40) ;;It is the standard deviation/sqrt (sample size)
75.894 is SE
To the nearest pound, z*SE=+/-196
CI = (3954,4346) units are pounds