SOLUTION: The average weight of 40 selected school buses was 4150 pounds. The standard deviation was 480 pounds. Find the 99% confidence interval of the true mean weight of all school buse

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Question 1141134: The average weight of 40 selected school buses was 4150 pounds. The standard deviation was 480 pounds. Find the 99% confidence interval of the true mean weight of all school buses.
type of interval (z or t)
estimate
z or t value
margin of error
interval
summary
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
Point estimate is 4150 pounds
use a t value with 39 df.is 2.71 for 99% CI
half-interval or margin of error is t*s/sqrt(n)=2.71*480/sqrt(40)[=205.67
interval is (3944, 4356)