Which of the following best represents the appropriate sample size to use when estimating an unknown population mean within 3 units, with 80% confidence if an estimate of the population standard deviation is 12? 44 62 27

Suppose that we are interested in how much money the average football fan spends on food at a single football game. To try to answer this, we asked 72 randomly selected football fans at a game how much money they had spent on food. The sampled results show that the sample mean and standard deviation were NZ$36.00 and NZ$14.65, respectively. Use the sample statistics to calculate an estimate of the standard error for the sample mean. Give your answer to 2 decimal places.

Suppose that you are interested in estimating the average number of miles per gallon of gasoline your car can get. You calculate the miles per gallon for each of the next sixteen times you fill the tank. Suppose that in truth, the values for your car are bell-shaped, with a mean of 24 miles per gallon and a standard deviation of 1. Find the possible sample means you are likely to get based on your sample of sixteen observations. Consider the intervals into which 68%, 95%, and almost all of the potential sample means will fall, using the Empirical Rule. (Round all answers to the nearest thousandth.)About 68% of possible sample means will be in the range between_____  and_____.About 95% of possible sample means will be in the range between______ and______  .About 99.7% of possible sample means will be in the range between ____and_____  . You may need to use the appropriate table in the Appendix of Tables to answer this question.

2. The population standard deviation for the age of Fictional College students is 8.4 years. If we want to be 95% confident that the sample mean age is within one year of the true population mean age of Fictional College students, how many randomly selected Fictional College students must be surveyed?

Assume that a sample is used to estimate a population mean μ. Find the margin of error M.E. that corresponds to a sample of size 22 with a mean of 62.5 and a standard deviation of 9.6 at a confidence level of 80%.Report ME accurate to one decimal place because the sample statistics are presented with this accuracy. M.E. =

1.  An experimenter feels that a population standard deviation is no larger than 17.0and would like to construct a 95% two-sided t-interval for the population mean that has alength at most 2.8. What sample size would you recommend?

The president of a college wants to determine the mean number of units that college students take per semester. How large of a sample is required in order to be 99% sure that a sample mean will be off by no more than 1.25 units? An initial study suggested that the standard deviation is approximately 2.1 units.

Is the difference between the mean annual salaries of entry level architects in Denver, Colorado, and Lincoln, Nebraska, equal to $10,500? To decide, you select a random sample of entry level architects from each city. The results of each survey are shown. Assume the population standard deviations are o₁ =$6511 and 2 = $6192. At a = 0.01, what should you conclude? Entry level architects Entry level architects in Denver, CO x₁ = 58,300 n₁ = 39 In Lincoln, NE x2 = 54,240 n2 = 30 What are the null and alternative hypotheses for this test? OA. Ho: H₁₂ = 10,500 Ha: H₁-H2*10,500 OD. Ho: P₁-H2>10,500 Ha: H1-H₂s 10,500 Calculate the standardized test statistic. z= (Round to two decimal places as needed.) Determine the P-value. The P-value is (Round to three decimal places as needed.) What can you conclude about the data? OB. Ho: H1 H2S 10,500 Ha H1-H2>10,500 OC. Ho: H1 H2210,500 Ha H1-H2 <10,500 OE. Ho: H1 H2*10,500 Ha: 1-2=10,500 OA. Reject Ho. At the 1% level of significance, there is…

Suppose that you are interested in estimating the average number of miles per gallon of gasoline your car can get. You calculate the miles per gallon for each of the next twenty-one times you fill the tank. Suppose that in truth, the values for your car are bell-shaped, with a mean of 27 miles per gallon and a standard deviation of 1. Find the possible sample means you are likely to get based on your sample of twenty-one observations. What are the intervals into which 68%, 95%, and 99.7% of the potential sample means will fall, using the Empirical Rule? (Round your answers to three decimal places.) About 68% of possible sample means will be in the range between___ and___ . About 95% of possible sample means will be in the range between___ and___ . About 99.7% of possible sample means will be in the range between ___and ____.