Chapter 3 Statistics

25. Unbiased estimates are more appropriately used a. if the data are nominal or ordinal b. if the sample is an estimate of a population c. if n exceeds 100 d. to estimate the skewedness of a distribution

if the sample is an estimate of a population

28. In order to compute the standard deviation, the _________ would also need to be computed. a. median b. range c. mode d. mean

mean

5. To calculate variance, you must know the a. range b. mean c. mode d. median

mean

22. The _____________ is the sum of the absolute value of the deviations from the mean. a. mean deviation b. standard deviation c. variance d. range

mean deviation

1. _________ reflects how the scores differ from one another. a. Skewness b. Kurtosis c. Averageness d. Variability

Variability

3. __________ can be thought of as a measure of how scores within a database differ from each other. a. The mean b. The median c. Variability d. (N - 1)/M

Variability

4. A measure of how much each score in a group of scores differs from the mean is a. variability b. the mean c. the median d. the mode

Variability

2. Variance is __________ statistical tool. a. a descriptive b. an inferential c. a central tendency d. not a

a descriptive

11. The formula for the inclusive range is a. r = (h - l)/2 b. r = (h - l )- 1 c. r = (h - l) + 1 d. r = (l - h)

r=(h-l)+1

15. Which of the measures of variance should NOT be used to reach conclusions regarding how individual scores differ from one another? a. Variance b. Standard deviation c. Range d. Semi-variance

range

14. The __________ is used almost exclusively to get a very __________estimate of how wide or different scores are from one another. a. range / general b. standard deviation / broad c. range / specific d. variance / general

range/general

19. In the formula for the standard deviation, is a. sigma, which tells you to find the sum of what follows b. each individual score c. the mean of all the scores d. the standard deviation

sigma, which tells you to find the sum of what follows

6. Variability is also known as a. flux b. scattergram c. skewedness d. spread

spread

20. Which is NOT a step in calculating the standard deviation? a. Square each individual difference b. Square each of the X values and compute the sum of all the Y values c. Sum all of the squared deviations about the mean d. Divide the sum by n - 1

square each of the X values and compute the sum of all the Y values

13. The most frequently used measure of variability is the a. range b. variance c. mean d. standard deviation

standard deviation

16. The average amount of variability in a set of scores represents the a. variance b. standard deviation c. range d. measures of variability

standard deviation

27. The __________ can help us compare scores from two different distributions, even when the means and standard deviations are different. a. mean b. standard deviation c. variance d. range

standard deviation

33. Variance is _________. a. a measure of central tendency b. the square root of the standard deviation c. stated in different units of measurement than the standard deviation d. unaffected by extreme scores

stated in different units of measurement than the standard deviation

17. The standard deviation is best defined as a. the sum of the absolute value of the deviations from the mean b. the difference between the highest score and the lowest score c. how scores differ from one another d. the average distance from the mean

the average distance from the mean

18. If the standard deviation is large, then most likely, a. the mean is large b. the average distance of each score from the mean is large c. the data set is large d. the range of scores in a distribution is large

the average distance of each score from the mean is large

10. In the formula for calculating the range, r is a. the range b. the highest score c. the lowest score d. the average

the range

23. An unbiased estimate uses __________ in the denominator of the SD formula. a. 1 - n b. N c. n d. n - 1

n-1

34. If n = 24 and s = 1.56, then the variance equals a. 2.43 b. 1.25 c. 0.06 d. 0.065

2.43

9. The range for the following scores is: 29, 48, 22, 37, 55 a. 26 b. 33 c. 37 d. -33

33

21. If E(X-M)= 235, and n = 29, what is s? a. 8.10 b. 8.39 c. 44.41 d. 43.64

44.41

31. Which of the following statements is FALSE? a. The standard deviation and the variance are both measures of dispersion. b. The standard deviation and the variance use similar formulas. c. The standard deviation and the variance are both discussed in the "Results" sections of journal articles. d. The standard deviation and the variance are both tools of inferential statistics.

The standard deviation and the variance are both tools of inferential statistics

26. Which statement is most true? a. The closer the sample size is to the actual population, the more accurate the standard deviation will be. b. The closer the sample size is to the actual population, the less accurate the standard deviation will be. c. The closer the sample size is to the actual population, the smaller the standard deviation will be. d. The closer the sample size is to the actual population, the more skewed the data will be.

the closer the sample size is to the actual population, the more accurate the standard deviation will be.

12. What is the difference between exclusive range and inclusive range? a. The inclusive range is the highest score minus the lowest score plus 1 b. The exclusive range eliminates outliers before subtracting the highest score from the lowest score c. To calculate the inclusive range, the mean must first be calculated d. The exclusive range can only be calculated using nominal data

the inclusive range is the highest score minus the lowest score plus 1

8. The following statements are true about the range EXCEPT a. The range is the most general measure of variability. b. The range indicates the distance between the highest scores and the lowest score. c. The range is difficult to compute. d. The range is heavily influenced by outliers.

the range is difficult to compute

7. Three tools used to assess variability are a. the mean, the median and the mode b. the range, the standard deviation and the mean c. the variance, the measures of central tendency, and the standard deviation d. the range, the standard deviation and the variance

the range, the standard deviation and variance

30. The variance is a. the square root of the standard deviation b. the standard deviation squared c. the easiest formula to compute d. mean squared divided by n

the standard deviation squared

32. Variance is a. the standard deviation squared b. the mean squared c. the square root of the standard deviation d. the range divided by the mean

the standard variation squared

29. If s = 0 a. there is no variability in the set of scores b. there is too much variability to calculate c. there are extreme scores in your sample d. the values in your sample are very different from one another

there is no variability in the set of scores

24. Biased estimates are more appropriately used a. to estimate the skewedness of a distribution b. to describe characteristics of a sample c. to estimate a population parameter d. to describe the measures of central tendency

to describe characteristics of a sample