Which of the following distribution curves demonstrates the least ...

[casperchen82]

Which of the following distribution curves demonstrates the least amount of variation in the scores?
 
  a. The least amount of variation would be in the first curve.
  b. The least amount of variation would be in the second curve.
  c. The least amount of variation would be in the third curve.
  d. The amount of variation can't be defined by the curve.

Question 2

One hundred students took an exam; the mean of the test was 45, and the median was 38; seventy students scored below the mean, but three scored more than 96. This would represent what type of distribution?
 
  a. Normal
  b. Positively skewed
  c. Negatively skewed
  d. Leptokurtic

[xiazhe]

Answer to Question 1

ANS: A
Kurtosis explains the degree of peakedness of the distribution curve, which is related to the spread of the variance of scores. An extremely peaked curve is referred to as leptokurtic, an intermediate degree of kurtosis as mesokurtic, and a relatively flat curve as platykurtic. The less peaked the curve, the more variation is present.

Answer to Question 2

ANS: B
Any curve that is not symmetrical is referred to as skewed or asymmetrical. Skewness may be exhibited in the curve in a variety of ways. A curve may be positively skewed, which means that the largest portion of data is below the mean. A curve can also be negatively skewed, which means that the largest portion of data is above the mean. A normal curve is symmetric and has no skew. Few samples will be perfectly symmetrical; however, as the deviation from symmetry increases, the seriousness of the impact on statistical analysis increases. In a positively skewed distribution, the mean is greater than the median, which is greater than the mode. In a negatively skewed distribution, the mean is less than the median, which is less than the mode.