Historical Sales

1.The hours of study and the final exam grades have this type of relationship: ŷ = 6.75(hours) + 37.45. Based on this linear regression equation, estimate the expected grade for a student spending 8 hours studying. Round your answer to two decimal places.  91.45

2. Historical sales records show that 40% of all customers who enter a discount department store make a purchase. We are interested in calculating the probability that 3 of 5 customers make purchase. Choose the best answer of the following: a. This is an example of a Poisson probability experiment. b. This is an example of a Binomial probability experiment c. This is neither a Poisson nor a Binomial probability experiment d. Not enough information to determine the type of experiment 

3. Microfracture knee surgery has a 75% chance of success on patients with degenerative knees. The surgery is performed on 5 patients. Find the probability of the surgery being successful on less than 3 patients?  0.1035

4. It has been recorded that 10 people get killed by shark attack every year. What is the probability of having 3 or 4 people get killed by shark attack this year?  0.0265

5. The mode teaching hours for a full time faculty at a state university is eight hours per week. What does this tell you about the typical teaching hours for full time faculty at that university?a.Half the full time faculties teach less than eight hours per week while half teaches more than eight hours per week. b. The average teaching hours for full time faculty is eight hours per week. c. More full time faculty teaches eight hours per week than any other number of teaching hours. d. The number of teaching hours for full time faculty in not very consistent because eight is such a low number. 

6.Assuming that the data are normally distributed with a mean of 25 and a standard deviation of 1.25, what is the z-score for a value of 27?  1.6

7. The mean hours of Internet usage by adults in the US in claimed to be 25 hours per week. A hypothesis test is performed at a level of significance of 0.05 with a P-value of 0.08. Choose the best interpretation of the hypothesis test. a. Reject the null hypothesis; there is enough evidence to reject the claim that the mean of hours Internet usage by adults in the US is 25 hours per week. b. Reject the null hypothesis; there is enough evidence to support the claim that the mean hours Internet usage by adults in the US is 25 hours per week. c. Fail to reject the null hypothesis; there is not enough evidence to reject the claim that the mean hours of Internet usage by adults in the US is 25 hours per week. d. Fail to reject the null hypothesis; there is not enough evidence to support the claim that the mean hours of Internet usage by adults in the US is 25 hours per week. 

8. A result of an entry level exam reveals that more than 22% of students fail that exam. In a hypothesis test conducted at a level of significance of 2%, a P-value of 0.035 was obtained. Choose the best interpretation of the hypothesis test. a. Fail to reject the null hypothesis; there is not enough evidence to reject the claim that 22% of students fail the entry level exam. b.Fail to reject the null hypothesis; there is not enough evidence to support the claim that 22% of students fail the entry level exam. c.Reject the null hypothesis; there is enough evidence to reject the claim that 22% of students fail the entry level exam. d.Reject the null hypothesis; there is enough evidence to support the claim that 22% of students fail the entry level exam. 

9 A bank is going to choose between two systems A and B which helps in measuring customers waiting time. During the trial period, both systems showed an average waiting time of 10 minutes. Type A showed a standard deviation of 2 minutes while type B showed a standard deviation of 4 minutes. Which of the two systems the bank should choose? a. System A because in shows more consistency in measuring the average waiting time. b.System B because in shows more consistency in measuring the average waiting time. c.Either because their mean waiting time is the same in both systems. d.Neither because the given information is not enough to make a decision 

10. A jar contains balls of four different colors; red, blue, yellow and green. The total balls are divides as 40% red, 35% blue, 20% yellow, and 5% green. If you are to select one ball at random. Find the expected value of your winning amount if the payments are set to be $0, $5, $25, $70 for red, blue, yellow and green ball respectively. Winning amount 0 5 25 70 Probability 40% 35% 20% 5% The expected winning amount is $25.50 The expected winning amount is $14.50 The expected winning amount is $12.25 The expected winning amount is $10.25