Читать книгу Student Study Guide to Accompany Statistics Alive! - Wendy J. Steinberg - Страница 18

1 You are interested in using the most stable measure of central tendency. Which measure should you use?MeanMedianModeAll are equally stable.

2 How should you report central tendency when you have a bimodal distribution?Report the meanReport one modeReport the medianReport two modes

3 How many scores should you expect to fall above the mode?Fifty percent of the scoresThe mode should be the center, such that the numerical distance of the values above the mode is equal to the numerical distance of the scores below the mode.This would depend on the skew of the distribution.There is no set number of scores you should expect to fall above the mode.

4 In the following set of scores, what is the median: 9, 6, 6, 8, 4, 1, 10, 11?6.58.597

5 In the following set of scores, what is the median: 12, 4, 1, 2, 1, 6, 8?421.53

6 What is the difference between M and μ?M is for population means, and μ is for sample means.M is for sample means, and μ is for population means.M and μ have the same definition.M is for median, and μ is for mean.

7 A high school football team is having tryouts and asks five participants to throw a football. Here is how far each person threw the ball (in feet): 79, 84, 93, 166, 88. Which score would be considered an outlier?798493166

8 Using the information from Question 7, what would the mean of the distances with the outlier and the mean of the distances without the outlier be, respectively?102 and 8686 and 10286 and 8888 and 86

9 You are collecting data for a study on hospital service. You have obtained data from patients at 30 different hospitals who have completed a satisfaction survey. The measures of central tendency are as follows: mean = 50, median = 50, and mode = 50. What can you tell about all the scores you have collected?There are numerous outliers.The scale ranges from 1 to 50.The scores are distributed in a symmetrical shape.All the participants provided identical information.

The following information is the ice cream sales of an ice cream shop’s nine best-selling flavors in hundreds of scoops. Use this information to answer Questions 10 to 15.

 6, 8, 15, 10, 23, 17, 23, 32, 19

 10. What is the average number of ice cream scoops?16.5221718.9

 11. What is the modal number of ice cream scoops?17271523

 12. What is the median number of ice cream scoops?17193423

 13. How would you expect this distribution to appear without sketching it?SymmetricalPositively skewedNegatively skewedBimodal

 14. The owner of the ice cream shop does not like the shape of the distribution of recent sales. He would like a stronger negative skew. To adjust the distribution so that it is more negatively skewed, where must the owner add scores?Above the meanBelow the meanPrecisely at the meanA few extreme scores above the mean

 15. Here is the commute time (in hours) per day of seven people who work at the same company: 4, 1, 0.5, 0.75, 2, 0.25, 1.5 hr. What is the average amount of time it takes these people to commute?2.11.671.431.54

 16. Using the information from Question 15, the person with the 4-hr commute begins to work for a different company and is no longer included in the calculation. What is the new mean amount of time it takes for the remaining people to commute?1.451.071.471.0

 17. To replace the person with the 4-hr commute, the company hires a new person, who commutes only 0.1 hr to work each day (because he lives very close). What is the new mean amount of time it takes for the workers to commute? (Use information from Questions 15 and 16.)1.171.00.640.87

 18. Using the original set of scores (from Question 15), which measure of central tendency would best describe the distribution?MeanMedianModeNone

 19. A farmer is interested in finding out which vegetable is preferred by elementary school children. He asks them to select from the following categories: peas, broccoli, carrots, onions, and celery. Which measure of central tendency should he use to summarize his data?MeanMedianModeNone