1. From a population of 540 that is known to have a standard deviation of 1,368,...

1. From a population of 540 that is known to have a standard deviation of 1,368, a
sample of 60 individuals. The mean of this sample is found to be 6.2.

a) Find the standard error of the mean.
b) Construct an interval estimate around the sample mean, using
the standard error of the mean calculated for 96% of cases.

2. A test of car safety in the State of Carolina found that the
tire pressure for a sample of 62 tires was 24 pounds per square inch at
standard deviation 2.1 pounds per square inch.

a. Find the standard error of the mean:
b. Estimate the interval for this population for 95% of cases:

3. When a sample of 70 sales executives was surveyed regarding poor performance in
their company, 66% thought that the drop in sales was due to high temperatures
unusual during this year 2017.

a) Estimate the standard error and say what it means

Solutions

Expert Solution

Allowed to solve only one question per post. solved two questions to help you.

1. From a population of 540 that is known to have a standard deviation of 1.368, a sample of 60 individuals. The mean of this sample is found to be 6.2.

a) standard error of the mean = 0.176608σn=1.36860=0.176608

b)96% confidence interval =(5.8373, 6.5627)

2. A test of car safety in the State of Carolina found that the tire pressure for a sample of 62 tires was 24 pounds per square inch at standard deviation of 2.1 pounds per square inch. a. Find the standard error of the mean: b. Estimate the interval for this population for 95% of cases:

the standard error of the mean = 0.2667

95% confidence interval

orchestra answered 1 year ago

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