STATS - CHAPTER 5 LEARNING CHECKS

for a population with μ = 80 and σ = 12, what is the z-score corresponding to X = 92? +0.50 +1.00 +1.20 +12.00

+1.00

a sample with a mean of M = 50 and a SD of s = 12 is being transformed into z-scores. after the transformation, what is the SD for the sample of z-scores? 0 1 n - 1 n

1

in a population of scores, X = 45 corresponds to z = +2.00 and X = 30 corresponds to z = -1.00. what is the population mean? 30 35 37.5 40

35

in a population with μ = 60, a score of X = 58 corresponds to a z-score of z = -0.50. what is the population standard deviation? 1 2 4 CANNOT BE DETERMINED WITHOUT ADDITIONAL INFORMATION

4

a score of X = 59 comes from a distribution with μ = 63 and σ =8. this distribution is standardized to a new distribution with μ = 50 and σ = 10. what is the new value of the original score? 59 45 46 55

45

for a population with μ = 50 and σ = 10, what is the X value corresponding to z = 0.4? 50.4 10 54 10.4

54

in a sample, X = 70 corresponds to z = +2.00 and X = 65 corresponds to z = +1.00. what are the sample mean and standard deviation? M = 60 and s = 5 M = 60 and s = 10 M = 50 and s = 10 M = 50 and s = 5

M = 60 and s = 5

in a sample with a standard deviation of s = 8, a score of X = 64 corresponds to z = -0.50. what is the sample mean? M = 56 M = 60 M = 68 M = 72

M = 68

a set of scores has a mean of μ = 63 and a SD of σ = 8. if these scores are standardized so that the new distribution has μ = 50 and σ = 10, what new value would be obtained for a score of X = 59 from the original distribution? X = 54 X = 55 X = 1.00 IMPOSSIBLE TO DETERMINE WITHOUT MORE INFORMATION

X = 55

for a sample with M = 72 and s = 4, what is the X value corresponding to z = -2.00 X = 70 X = 68 X = 64 X = 60

X = 64

a z-score of z = +1.00 indicates a position in a distribution ___. ABOVE THE MEAN BY 1 POINT ABOVE THE MEAN BY A DISTANCE EQUAL TO 1 STANDARD DEVIATION BELOW THE MEAN BY 1 POINT BELOW THE MEAN BY A DISTANCE OF EQUAL TO 1 STANDARD DEVIATION

above the mean by a distance equal to 1 standard deviation

what location in a distribution corresponds to z = -2.00? ABOVE THE MEAN BY 2 POINTS ABOVE THE MEAN BY A DISTANCE EQUAL TO 2 SD BELOW THE MEAN BY 2 BELOW THE MEAN BY A DISTANCE EQUAL TO 2 SD

below the mean by a distance equal to 2 standard deviations

last week Andi had exams in chemistry and in spanish. on the chemistry exam, the mean was μ = 30 with σ = 5, and Andi had a score of X = 45. on the spanish exam, the mean was μ = 60 with σ = 6 and Andi had a score of X = 65. for which class should Andi expect the better grade? CHEMISTRY SPANISH THERE IS NOT ENOUGH INFORMATION TO KNOW

chemistry

T/F: a score close to the mean has a z-score close to 1.00

false

T/F: if a sample of n = 10 scores is transformed into z-scores, there will be five positive z-scores and five negative z-scores

false

T/F: if μ = 40 and 50 corresponds to z = +2.00 then σ = 10 points

false

if σ = 20, a score above the mean by 10 points will have z = 1.00

false

for the past 30 years, the high temperature on April 15th has averaged μ = 62 with a SD of σ = 4. last year, the high temp was 72 degrees. based on this information, last year's temp on April 15th was _____. A LITTLE ABOVE AVERAGE FAR ABOVE AVERAGE ABOVE AVERAGE, BUT IT'S IMPOSSIBLE TO DESCRIBE HOW MUCH ABOVE AVERAGE THERE IS NOT ENOUGH INFORMATION TO COMPARE LAST YEAR WITH THE AVERAGE

far above the average

last week Sarah had exams in math and in spanish. on the math exam, the mean was μ = 30 with σ = 5, and Sarah had a score of X = 45. On the spanish exam, the mean was μ = 60 with σ = 6 and Sarah had a score of X = 65. for which class would Sarah expect the better grade? MATH SPANISH THE GRADES SHOULD BE THE SAME BECAUSE THE TWO EXAM SCORE ARE IN THE SAME LOCATION THERE IS NOT ENOUGH INFO TO DETERMINE WHICH IS THE BETTER GRADE

math

using z-scores, a sample with M = 37 and s = 6 is standardized so that the new mean is M = 50 and s = 10. how does an individual's z-score in the new distribution compare with his/her z-score in the original sample? new z = old z +13 new z + (10/6)(old z) new z = old z cannot be determined with the information given

new z = old z

which of the following is an advantage of transforming X values into z-scores? ALL NEGATIVE NUMBERS ARE ELIMINATED THE DISTRIBUTION IS TRANSFORMED TO A NORMAL SHAPE ALL SCORES ARE MOVED CLOSER TO THE MEAN NONE OF THE OTHER OPTIONS IS AN ADVANTAGE

none of the other options is an advantage

T/F: a negative z-score always indicates a location below the mean

true

T/F: transforming an entire distribution of scores into z-scores will not change the shape of the distribution

true

under what circumstances would a score that is 15 points above the mean be considered an extreme score? WHEN THE MEAN IS MUCH LARGER THAN 15 WHEN THE SD IS MUCH LARGER THAN 15 WHEN THE MEAN IS MUCH SMALLER THAN 15 WHEN THE SD IS MUCH SMALLER THAN 15

when the standard deviation is much smaller than 15

a population with μ = 80 and σ = 15 is transformed into z-scores. after the transformation, what is the mean for the population of z-scores? μ = 80 μ = 1.00 μ = 0 CANNOT BE DETERMINED FROM THE INFORMATION GIVEN

μ = 0

a score of X = 73 is obtained from a population. which set of population parameters would make X - 73 an extreme, unrepresentative score? μ = 65 and σ = 8 μ = 65 and σ = 3 μ = 70 and σ = 8 μ = 70 and σ = 3

μ = 65 and σ = 3