(For problems 1 to 7) The checkout times (in minutes) for 12 randomly selected customers at an electronic store during the stores busiest time are as follows:

5.0	8.4	6.0	8.0	11.0	9.5
12.7	6.5	10.0	9.0	6.5	13.0

1. (Show work) What is the mean checkout times based on the 12 checkout times. (Round the answers to two decimal places)

2. (Show work) Give a 5-number summary of the checkout time. (Round the answers to two decimal places)

3. Prepare a frequency distribution with a class width of 2 minutes (with the first class as 4.0 5.9, etc.).

4. Identify the class midpoints for frequency distribution from Question 3. (Round the answers to two decimal places) (Show Work)

5. (Show work) Construct the relative frequency distribution based on the frequency distribution from Question 3. (Round the percentage to one decimal place)

6. (Show work) Normally a student would find the mean checkout time based on the raw data. Now suppose that we dont have the raw data, but instead, we only have the frequency distribution. Find the mean checkout time based on the frequency distribution from Question 3. (Round the answer to two decimal places) Compare your results with the "actual" mean checkout time you found in Question 1.

7. (Show work) Find the standard deviation of the checkout time based on the frequency distribution from Question 3. Please show your calculation in the following table. (Round the answer to two decimal places)

Check-out time	Frequency f	Mid-point x	x2	f * x2	f * x
4.0 5.9
Sum

(For Problems 8, 9 & 10) To qualify for a mortgage, an applicant needs to have a good FICO credit score. We chose a random sample of 6 applicants from a local bank, and their FICO scores are 710, 740, 655, 810, 560 and 600.

8. (Show work) What is the standard deviation of the FICO scores in the sample? Please show your calculation in the following table; you may not need all columns based on the formula you use. (Round the answer to two decimal places)

FICO Score x	x2	x-mean	(x-mean)2
710
740
655
810
560
600
Sum

9. (Show work) Are any of these FICO scores considered unusual in the sense of our textbook? Explain.

10. (Show work) What is the coefficient of variation in FICO scores of the sample? (Round the answer to two decimal places)

11. Determine whether the given value is a parameter or statistics. Please explain your answer.

(a) An organization conducts a survey on the choice of fruit by Europeans. It is reported by the organization that 61% of the respondents prefers apple.

(b) A teacher randomly picked 200 students and found the average study time is 25.2 hours per week.

12. Robert is a recent college graduate, who is considering a possible career in the engineering. One factor that will affect her decision is how much money he is likely to make. He got salary information from Internet. Since you are taking a Statistics course, he would like to get your opinion on whether mean salary or median salary information is more useful for her. What would be your recommendation? Please explain your answer.