Chapter 5 Stats

Which of the following is an advantage of transforming raw scores into z-scores? The distribution is transformed into a normal shape. All scores are moved closer to the mean. All negative numbers are eliminated. None of these options are an advantage.

None of these options are an advantage.

The direct, unchanged scores that are the direct result of measurement are called raw scores. z-scores. deviation scores. standardized scores.

raw scores

You have a score of X = 65 on an exam. Which set of parameters would give you the best grade on the exam? µ = 70 and σ = 5 µ = 60 and σ = 5 µ = 70 and σ = 10 µ = 60 and σ = 10

µ = 60 and σ = 5

A population has µ = 50. What value of σ would make X = 55 a more central, representative score in the population? σ = 1 σ = 20 σ = 10 σ = 5

σ = 20

Which of the following represents the deviation score? X s² μ (X - μ)

(X - μ)

For a population with σ = 10, a score that is located 20 points above the mean would have a z-score of _____. Cannot be determined without knowing the value of the mean +2.00 +20.00 -2.00

+2.00

A population with µ = 30, a score of X = 24 corresponds to z = -2.00. The standard deviation for the population is σ = 6. True False

False

Which of the following z-scores represents the location closest to the mean? -0.25 -2.50 +1.25 +0.75

-0.25

Of the following z-score values, which one represents the most extreme location on the left-hand side of the distribution? +2.00 -1.00 -2.00 +1.00

-2.00

The mean for any distribution corresponds to a z-score of _____. 1 N Cannot be determined from the information given. 0

0

If a population with μ = 122.51 and σ = 17.45 is transformed into z-scores, then the resulting distribution of z-scores will have a mean of _____ and a standard deviation of _____. 0; 17.45 122.51; 17.45 122.51; 1 0; 1

0;1

What position in the distribution corresponds to a z-score of z = -1.50? Below the mean by a distance equal to 1.50 standard deviations Above the mean by 1.50 points Above the mean by a distance equal to 1.50 standard deviations Below the mean by 1.50 points

Below the mean by a distance equal to 1.50 standard deviations

A raw score with a value less than or equal to the mean will have a z-score that is less than or equal to 0. True False

True

Because all z-score distributions have the same mean and standard deviation, the z-score distribution is called a standardized distribution. True False

True

A z-score of z = +3.00 indicates a location that is the location depends on the mean and standard deviation for the distribution. slightly above the mean. far above the mean in the extreme right-hand tail of the distribution. near the center of the distribution.

far above the mean in the extreme right-hand tail of the distribution.

A very bright student is described as having an IQ that is three standard deviations above the mean. If this student's IQ is reported as a z-score, the z-score would be _____. μ + 3σ Cannot be determined from the information given. μ + 3 +3.00

+3.00

Any individual with a negative z-score has a raw score greater than the mean. True False

False

In a distribution with s = 20, a score that is above the mean by 10 points will have a z-score of z = -0.50. True False

False

For a population with a mean of µ = 72, any score greater than 72 will have a positive z-score. True False

True

For any distribution of scores, the location identified by z = +1.00 and the location identified by z = -1.00 are exactly the same distance from the mean. True False

True

If two individuals in the same population have identical X values, they also will have identical z-scores. True False

True

Standardized scores are "simple" values for the mean and standard deviation that do not change any individual's location within the distribution. True False

True

The process of transforming every X value in a distribution into a corresponding z-score to create a distribution of z-scores is called a z-score transformation. True False

True

Under what circumstances is a score that is located 5 points above the mean considered a central value that is relatively close to the mean? When the population standard deviation is much greater than 5. When the population mean is much greater than 5. When the population mean is much less than 5. When the population standard deviation is much less than 5.

When the population standard deviation is much greater than 5.

Under what circumstances is a score that is 15 points above the mean an extreme score relatively far from the mean? When the population mean is much smaller than 15 When the population standard deviation is much larger than 15 When the population standard deviation is much smaller than 15 When the population mean is much larger than 15

When the population standard deviation is much smaller than 15