Scenario 38-5. Researchers are interested in the height of the average person in San Francisco, California. Using a random sample of 1,000 people, they find that the average height in the sample is 68 inches. Refer to Scenario 38-5. What can you say about the sample and the results of the research? 000 The sample suffers from too much uncertainty. The finding has a huge margin of error. The sample is likely to be representative of the population because of the randomness. The sample is not representative of the population because of the randomness.

Question 1 It is necessarý for an automobile producer to test the hypothesis that the mean number of miles per gallon achieved by its cars is 28 against the alternative hypothesis that it is not 28. The standard deviation of the number of miles per gallon achieved by the company's cars is 6. Suppose that the mean number of miles per gallon for a sample of 100 cars is 26.2. On the basis of this result, should the company reject the hypothesis that the population mean is 28? Why, or why not? Use a=0.05.

An econometrics class has 80 students, and the mean student weight is145 lb. A random sample of 4 students is selected from the class, and theiraverage weight is calculated. Will the average weight of the students in thesample equal 145 lb? Why or why not? Use this example to explain whythe sample average, Y, is a random variable ?

The standard deviation of the scores on a skill evaluation test is 363 points with a mean of 1239 points. If 335 tests are sampled, what is the probability that the mean of the sample would differ from the population mean by less than 23 points? Round your answer to four decimal places.

Suppose the amount of change IWU students carry is exponentially distributed with a mean of $0.88. Suppose that we randomly pick 25 IWU students and learn how much change they have. What type of distribution does the population, which is the change carried by IWU students, follow? What are the mean and standard deviation of the population? (6 points)           What type of distribution does the sample mean follow? What are the mean and standard deviation of the sample mean? (6 points)           Find the probability that the average change of 25 IWU students was between $0.80 and $1.00. Graph the situation, shade in the area to be determined, and find the probability. (6 points)

QUESTION 8 Having an extreme score in a sample (outliers) will NOT effect which of the following?     standard deviation     mean     mode     variance

Suppose a random sample of size 54 is selected from a population with o = 11. Find the value of the standard error of the mean in each of the following cases (use the finite population correction factor if appropriate). a. The population size is infinite (to 2 decimals). b. The population size is N = 50,000 (to 2 decimals). %3D c. The population size is N = 5000 (to 2 decimals). d. The population size is N = 500 (to 2 decimals).

A courier service company wishes to estimate the proportion of people in various states that will use its services.  Suppose the true proportion is 0.05 . If 273 are sampled, what is the probability that the sample proportion will differ from the population proportion by less than 0.03 ? Round your answer to four decimal places.

The director of Computer Associates, Inc (CAI) has been assigned the task of developing the profile of the company’s employees. The characteristics identified include the annual salary and if the employee completed the company’s management trainee program. Data for ALL employees (the population) is presented in the Worksheet CAI. The data on employees is assumed to be normally distributed. a. What is the probability that a random sample of 64 employees will provide a sample mean within $1,000 of the population mean? (USE 4 DECIMALS) b. What is the probability that a random sample of 64 employees will provide a sample mean that is $500 greater than the population mean? (USE 4 DECIMALS) c. What is the probability that a random sample of 64 employees will provide a sample mean that is $400 less than the population mean? (USE 4 DECIMALS) d. What is the probability that a random sample of 64 employees will provide a sample proportion within 0.10 of the population proportion? (4 DECIMALS) e.…

Suppose a batch of steel rods produced at a steel plant have a mean length of 150 millimeters, and a variance of 100. If 275 rods are sampled at random from the batch, what is the probability that the mean length of the sample rods would differ from the population mean by greater than 0.57 millimeters? Round your answer to four decimal places.