Practice: Statistical Measures

Part A: Find Mean, Median, Mode, and Range

Directions: For each data set, calculate all four statistical measures. Remember to order the data first!

1. Test scores: 75, 82, 90, 82, 86

Mean	Median	Mode	Range

2. Ages of cousins: 8, 12, 15, 10, 12, 9

Mean	Median	Mode	Range

3. Daily temperatures (F): 68, 72, 75, 70, 65, 72, 78

Mean	Median	Mode	Range

4. Points scored: 14, 22, 18, 14, 20, 14, 16

Mean	Median	Mode	Range

Directions: Calculate the measures and analyze how outliers affect them.

5. Weekly allowances: $10, $12, $15, $10, $100

Mean = Median =

Which value is the outlier?

Which measure (mean or median) better represents a typical allowance? ____________

6. Home prices: $200,000, $220,000, $215,000, $210,000, $1,500,000

Mean = Median =

Why would a real estate agent prefer to advertise the median price? _______________

7. If you remove the outlier from Problem 5, what is the new mean?

New data: $10, $12, $15, $10

New Mean =

How much did removing the outlier change the mean?

Directions: Decide which measure of center (mean, median, or mode) is most appropriate.

8. A shoe store wants to know what size to stock the most of. Which measure should they use?

Best measure: ____________ Reason: _______________________________

9. A teacher wants to find the "average" score on a test where most students scored between 70-90 but one student scored 25. Which measure?

Best measure: ____________ Reason: _______________________________

10. A basketball coach wants to know the team's typical score when the data is evenly spread with no outliers. Which measure?

Best measure: ____________ Reason: _______________________________

Directions: Read each problem carefully. Show your work.

11. Maria's quiz scores are 88, 92, 85, 90, and 95. What is her mean score? If she wants a mean of 92 after her next quiz, what score does she need?

Current mean =

Needed score on next quiz =

12. The number of books read by 8 students: 2, 5, 3, 7, 4, 5, 6, 4. Find the mean, median, and mode.

Mean = Median = Mode =

13. A data set has a mean of 15, a median of 12, and a mode of 10. Which statement is true?

A) The data has no outliers B) There is an outlier pulling the mean up

C) The mode is the best measure D) All measures are equal

Answer: _____ Explain: _______________________________

14. Create a data set of 5 numbers where the mean, median, and mode are all equal to 10.

Your data set: _____, _____, _____, _____, _____

15. The mean of 6 numbers is 20. Five of the numbers are 15, 18, 22, 24, and 19. What is the sixth number?

Sixth number =

Hint: If mean = 20 and there are 6 numbers, what must the total be?