Health Stats Ch. 13
The empirical rule applies to a normal, bell-shaped curve (distribution) and indicates the percent of scores that lie within each standard deviation from the mean; within + or - 1 SD = 68%; + or - 2 SDs = 95%; + or - 3 SDs = 99.7%.
true
The symbol Σ represents: a. sample b. population c. sum d. average
c. sum
Measures of dispersion (variation) include the range, variance, and standard deviation. a. True b. False
a. True
Skewed distributions affect measures of central tendency, moving the mean in the direction of the skewness and moving the median between the mean and mode. a. True b. False
a. True
Standard deviation is the square root of the variance. a. True b. False
a. True
The arithmetic mean is the most commonly used measure of central tendency. a. True b. False
a. True
The mode is the most frequently occurring score. a. True b. False
a. True
The terms dispersion, spread, and variation have the same meaning. a. True b. False
a. True
The values of the variance and standard deviation are never negative. a. True b. False
a. True
Variance and standard deviation can be calculated from either ungrouped or grouped data. a. True b. False
a. True
A weighted mean is used if certain components are less significant than others. a. True b. False
b. False
The mean is the middle score in a data set, when scores are arranged in order of magnitude. a. True b. False
b. False
The range is the difference between the midpoint and the largest value. a. True b. False
b. False
The ____ is the midpoint of a distribution, or the point above which 50% of the scores lie, and below which the other 50% lie. a. mean b. median c. mode d. sum
b. median
The mean is computed by adding all the scores in a distribution and ____ by the total number of scores in the distribution. a. squaring b. multiplying c. dividing d. None of the above
c. dividing
The ____ of a set of numbers is the score that occurs with the greatest frequency; that is, the most common value in a data set. a. mean b. median c. mode d. sum
c. mode
Curves that have scores concentrated at either the high or low end of the curve are called ____ curves. a. bimodal b. modal c. symmetrical d. skewed
d. skewed