# Help with statistics homework

**Question description**

1) A survey of 38 randomly selected iPhone owners showed that the purchase price has a mean of $416 with a sample standard deviation of $170. Compute the standard error of the sample mean

Standard error

2) A sample of 260 observation is selected from a normal population for which the population standard deviation is known to be 27. The sample error of the mean is 17

a) Determine the standard error of the mean. (Round your answer to 3 decimal places.)

Standard error of the mean

C) Determine a 95% confidence interval for the population mean (Round your answers to 3 decimal places)

Confidence interval

3) Bob Nale is the owner of Nale's Quick Fill. Bob would like to estimate the mean number of gallons of gasoline sold to his customers.Assume the number of gallons sold follows the normal distribution with a population standard deviation of 2.50 gallons. From his records he selects a random sample of 45 sales and finds the mean number of gallons sold at 8.30

a) What is the point estimate of the population mean? (Round your answer to 2 decimal places)

Point estimate

b) Determine a 95% confidence interval for the population mean (Round your answer to 2 decimal places)

Confidence interval

4) The Fox TV network is considering replacing one of its prime-time crime investigation shows with a new family oriented comedy show. Before a final decision is made, network executives commission a sample of 350 viewer. After viewing the comedy 200 indicated they would watch the new show and suggested it replace the crime investigation show

a) Estimate the value of the population proportion (Round your answer to 3 decimal places

Population proportion

b) Determine the 95% confidence interval for the population proportion (Round your answer to 3 decimal places)

Confidence interval

5)A population is estimated to have a standard deviation of 8. We want to estimate the population mean within 2 with a 90% level of confidence

How large a sample is required? (Round up your answer to the next whole number)

Sample required is

6) The estimate of the population is to be within plus or minus 0.05, with a 95% level of confidence. The best estimate of the population proportion is 0.15. How large a sample is required? (Round up your answer to the next whole number)

Sample size

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