Question

Question 3: New 2018 Ford Royal for a sample of 10 tanks of gas was 45.5 with a standard deviation of 1.8. For a 2018 Buick Executive, the average mpg usage for a sample of 10 tanks of gas was 42.1with a standard deviation of 2.3. Unknown but variances assumed equal, at α = .01, is the true mean mpg lower for the Buick Executive?

1. For H₀: μ_Ford – μ_Buick ≤ 0; H₁: μ_Ford – μ_Buick > 0. Reject H₀ if ______________________

2. Computed test statistics up to four decimals is _________________________________________ When x-bar is $118,000 with $30,000 population Standard deviation for 40 sales people.

3. Is true mean mpg lower for the Buick Executive? Pick One:          YES        |             NO

Question 4. Jane & John Sales is a new talk in town in aerospace industry; they are getting a lot of media coverage. To retain the best sales talent, HR at Jane & John claims that they paid $125,500 in yearly bonuses to its sales force.

The CEO of Aero No-space Sales, direct competitor and old timer is frustrated. According to the CEO, there is no way bonuses can equal $125,000. He is 95% confidence that claimed yearly bonuses does not equal $125,500.

1. Formal Null and Alternative Hypothesis are stated as:

___________________________________

___________________________________

2. Computed test statistics value is ____________________________________________________
3. Using the table the looked-up p-value for the computed test statistics is _____________________

Answer 1

The level of significance is . The sample sizes are .

The hypotheses are

This is right -tailed T-test.

b)The test statistic is . We use pooled variance since the variances are equal and unknown. Here

Thus,

a) Reject if   (i.e test statistic greater than critical value). Which is true.

c) So we reject the null hypothesis at 99% confidence. Conclusion is

"True mean mpg is lower for the Buick Executive"   YES