A highway inspector needs an estimate of the mean weight of trucks crossing a bridge on the interstate highway system. she selects a random sample of 49 trucks and finds a mean of 15.8 tons with a sample standard deviation of 3.85 tons. the 90 percent confidence interval for the population mean is:

14.90 to 16.70 tons

Step-by-step explanation:

We are given;

Sample size; n = 49

Mean; x¯ = 15.8

Sample standard deviation; s = 3.85

At 90% Confidence interval, z = 1.645

Formula for confidence interval is;

CI = x¯ ± z(s/√n)

Thus;

CI = 15.8 ± 1.645(3.85/√49)

CI = 15.8 ± 0.90

CI = 14.90 to 16.70 tons

we'll this would mean that the dunk tank and the bounce house are the same for 20 hours because the 2 represents that the two activities, and the 20 represents the amount of hours they both are. so with this said, it means that the answer is c. the costs for a dunk tank and bounce house are the same for 20 hours.

c.the costs for a dunk tank and bounce house are the same for 20 hours.

hope this .

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step-by-step explanation: