1. Recommended t1re pressure IS 34 p51. A sample taken from b' Goodrich tires from AV1s showed a sample average of 32 and standard deviation of 2. Does Avis average tire pressure differ for the recommended 34 psi? Test Type: 2 t d , Chi SQ , F , Confidence interval , Answer Significant difference Avis Sample average versus recommended: Yes No 2. Tires were made by Goodrich. Avis asked Goodrich and was told that the average pressure for Goodrich Tirn is 34 and the standard deviation of their tires = 3. Does this new information changes the significance answer t Question 1 about the Avis tires (sample 6 tires, average of 32 and standard deviation of 2) Test Type: 2 t d , Chi SQ , F , Confidence interval , Answer Significant difference Avis Sample average versus recommended: Yes No 3. Based on question 2, what is the acceptable average range for a sample of 6 Goodrich tires? Test Type: 2 t , d , Chi SQ , F , Confidence interval , Answer Acceptable average range of sample of 4 tires +/- ' Formula: 4. Avis then checked Hertz tires. A sample of 11 Hertz tires had an average of 35 psi and standard deviation: 2.5. Is there a significant difference between Avis and Hertz tires samples based on the sample in Question 1 (1 sample taken from 6 tires from Avis showed a sample average of 32 and stande deviation of 2)? Test Type: 2 t d , Chi SQ , F , Confidence interval , Answer Significant difference sample average Avis versus Hertz: Yes No ' 5. For a Hertz sample of 11 tires, sample average 35 and sample standard deviation of 2.5. What is the 90% confidence interval (two sided)? Test Type: 2 , t , d , Chi SQ , F , Confidence interval , 90% Confidence Interval (two sided) Hertz sample average +/- 6. If you compare the Hertz 11 tire sample and standard deviation of 2.5 to the Goodrich population standard deviation of 3, is the Hertz sample standard deviation significantly different than the Goodrich population Standard deviation? Test Type: Z t d , Chi SQ , F Answer significant difference sample std. deviation Hertz versus Goodrich: Yes , Confidence interval , No 7. If you compare the Hertz 11 tire sample and standard deviation of 2.5 to an Avis 6 tire sample standard deviation of 2, is the Hertz sample standard deviation significantly different than the Avis sample standard deviation (note: please extrapolate from the table formulas)? Test Type: 2 t d , Chi SQ , F , Confidence interval , Answer significant difference sample std. deviation Avis versus Goodrich: Yes No 8. Avis finally decided to take another sample and they wanted to make sure that the error is less than 2 psi. Based on the Goodrich information of average = 34 psi and standard deviation of 3, what is the sample size Formulas: n = Show Calculations
