1. What is a null hypothesis ?

a. the statement that will be accepted if the statement under investigation is rejected b. the level of significance of the statement under investigation in a statistical test c.the amout of risk one is willing to take in rejecting the statement under investivation in a statistical test d. the statement under investigation in a statistical test 2. What is the level of significance of a test? a. the probability of accepting null hypothesis when it is true b the probability of rejecting alternate hypothesis when it is true c. the probability of accepting alternate hypothesis when it is true d. the probability of rejecting null hypothesis when it is true 3.

Let x be a random variable that represents assembly times of a Lexus R350. The company reported the average assembly time is Ã‚µ=38 hours, with a standard deviation (sigma) of 1.2 hours. An engineer developed a modification in the process that is believed to reduce the assembly time. When a Radom sample of 47 vehicles being completed, the sample mean (x-bar)=37.5 Use ? = 0.01 and find the P-Value.

a. 0.061

b. 0.0021

c. 1.109

d. 0.261

4. Using the P-Value from the Lexus problem in number 3, and the null hypothesis of Ã‚µ=38 hours, . a.Accept the Null hypothesis because P <.01

b. Accept the Null hypothesis because P >.01

c. Reject the Null hypothesis because P >.01

d. Reject the Null hypothesis because P <.01 5. A student has computed that it takes an average (mean) of 17 minutes with a standard deviation of 4 minutes to drive from home, park the car, and walk to an early morning class. One day it took the student 25 minutes to get to class. How many standard deviations from the average is that? 6. A student has computed that it takes an average (mean) of 16 minutes with a standard deviation of 4 minutes to drive from home, park the car, and walk to an early morning class. Another day it only took the student 12 minutes to get to class. What is the measurement in standard units (Hint: remember that a standard unit is a z score)? 7. Erin’s z score on a college entrance exam is 1.5. If the raw scores have a mean of 490 and a standard deviation of 40 points, what is her raw score? 8. Determine the number of different groups of 4 questions a teacher could select from a set of 10 distinct questions. 9.

- If a club has 10 members:* Find the number of different slates of 3 officers (list of president, vice-president, and treasurer) that the club could have for officers. 10. Find the number of different slates of 4 officers (list of president, vice-president, secretary, and treasurer) that the club could have for officers.