C6 Quiz

• For normal distributions, percentile ranks  tend to exaggerate differences between persons at the middle of the scale.
• In a normal distribution, the interscore distance would be greatest for the interval P₅ - P₁₀.
• A set of raw scores (mean=48, S=9) is transformed to a set of IQ scores (mean=100, S=15). A raw score of 45 is equivalent to an IQ score of 95.
• Standard scores obtained from different distributions may be compared if the reference groups are comparable and if the shapes of the distributions are similar,
• The standard deviation of a set of z scores is the same as the standard deviation of the set of raw scores if they are normally distributed.
• z scores from two different score distributions are comparable only if the reference groups are equivalent.
• That the distribution follows the normal curve is not a necessary characteristic of a set of standard scores.
• In a normal distribution with mean=50, S=10  and  the middle 50% of cases fall between 43 and 57 (rounded).   
• In a normal distribution with  mean=50, S=10 the bottom 80% of the cases fall below score 58 (rounded)
• In a normal distribution of 200 cases, the bottom 40 cases fall below z score .-84.
• In a normal distribution of 400 scores with  mean = 50 and s = 10  27 fall below 35?
• In a normal distribution with mean = 50   and  S = 10,  the proportion of cases that falls between 45 and 55 is .3830?
• If we know the mean and standard deviation of a population, then any individual's raw score can be converted to a z-score using the formula z=(X - M)/S.
• In a normal distribution of 200 cases, 21 fall above z=+1.25.
• The percent of cases in a normal distribution falling between z=+.67 and  z=-.67 is approximately .50.
• In a normal distribution of 200 cases, 173 fall between z = +1.5 and z = -1.5.
• If a set of raw scores is positively skewed, the set of  scores derived from them will be positively skewed.
• The mean of a normal curve does not take various values.
• In a normal distribution of 200 cases, the bottom 40 cases fall below what  score? -.84
• In a normal distribution of 200 cases, what  score divides the top 20 cases from the bottom 180? +1.28
• In a normal distribution with   and  the bottom 80% of the cases fall below what score (rounded)? 58
• In a normal distribution with   and  the middle 50% of cases fall between what two scores (rounded)? 43 and 57
• A score of 650 is earned on a test for which  and  An equivalent score on a scale where  and  is 115.
• In a normal distribution of x-bar=110, S=10, P₁₈  is a score of (rounded) 41.