Question 1 (8 points) Part (a) The following information is given 4 points) Ho i

Question

Question 1 (8 points) Part (a) The following information is given 4 points) Ho is that the mean speed of cars driving down Hamburg Turnpike is 40 miles per hour or less The sample consists of 19 cars driving down Hamburg Turnpike. Their mean speed is 42 miles per hour = 0.05 If it is possible to determine the critical value(s) based on this information, determine it/them. If it is not possible, explain why it is not possible Continued on p. .2 Part (b) Part (b) is independent from Part (a), i.e., do not use informationm from Part (a) to answer Part (b) The following information is given (4 points) The null hypothesis is that the population variance of middle school teachers' salaries is the same as the population variance of entry-level accountants' salaries The significance level is 0.05 The sample standard deviation of middle school teachers' salaries is $11,554 and the sample standard deviation of entry-level accountants' salaries is $9,776 - If it is possible to determine the critical value(s) based on this information, determine it/them. If it is not possible, explain why it is not possible Question 2 (4 points) Part (a) The "Cars.xlsx" data set has information on the mileage of both domestic and foreign cars. Using - 0.05, carry out an F-test in Excel to test whether the population variances of the mileage between the two types of car are equal You must submit your actual Excel file with the output as part of the assignment. (2 points) (2 points) Part (b) Based on the F-test, what is your decision ("reject" or "do not reject") regarding the null hypothesis that the two population variances are equal to each other? Indicate on which part of the Excel output you base your decision. Question 3 (6 points) Part (a) Still using the "Cars.xlsx" file, carry out a t-test in Excel (with -0.05) that tests whether the population means of the mileage between the two types of car are equal. Note that the decision of (2 points) Page 1 of2

Explanation / Answer

a)
H0: Mean speed of cars driving down Hamburg Turnpike < 40 miles per hr

Sample size, n = 19
So, degree of freedom = n - 1 = 19 - 1 = 18
Critical value of t for significance level of 0.05 and df = 18 is 2.1

Now, critical value of mean speed, Vc is given as,
Critical value of t = (Vc - 40) / Standard error

So, we need to know the standard error of the mean speed of cars driving down Hamburg Turnpike to calculate the critical value of mean speed.
Standard error can be calculated from the standard deviation of speed of cars driving down Hamburg Turnpike.
As, we do not have the information of standard deviation of speed of cars, it is not possible to calculate the critical value.

b)
H0: Population variance of middle school teachers salaries = Population variance of entry level accountants salaries. That is s1 = s2.

Test statistic F = s1 / s2 = 11554 / 9776 = 1.18

Now, to determine the critical values, we need degree of freedoms for F test statistic.
Degree of freedom are derived from the sample size of middle school teachers salaries and entry level accountants salaries.

As, we do not know the sample size of middle school teachers salaries and entry level accountants salaries, it is not possible to determine the critical values.

Related Questions

Navigate

• Browse (All)
• Browse Q
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.