Question

homework check please =)

1. A distribution has a standard deviation of σ = 10. Find the z-score for each of the following locations in the distribution.

1. Above the mean by 5 points.

Answer: ___.5___________

2. Above the mean by 2 points.

Answer: ______.2___________

3. Below the mean by 20 points.

Answer: ______-2__________

4. Below the mean by 15 points.

Answer: ________-1.5_______

2. For a distribution with a standard deviation of σ = 20, describe the location of each of the following z-scores in terms of its position relative to the mean. For example, = +1.00 is a location that is 20 points above the mean.

1. z = +2.00

Answer: __40 above the mean_________

2. z = +.50

Answer: ___20 above the mean ________

3. z = -1.00

Answer: ___10 below the mean ________

4. z = -0.25

Answer: ___5 below the mean _________

3. For a population with μ = 80 and σ = 10,

a. Find the z-score for each of the following X values. (Note: You should be able to find these values using the definition of a z-score. You should not need to use a formula or do any serious calculations.)

X = 75:    z =_-0.55____ X = 100: z = _1.95___            X = 60: z = __-2.05___

X = 95:    z=__1.50____   X = 50: z =__-.3.05____         X = 85 z = __0.45____

2. Find the score (X value) that corresponds to each of the following z-scores. (Again, you should not need a formula or any serious calculations.)

z = 1.00: X= __90__                    z = 0.20: X=_82_____ z = 1.50: X= _95___

z = -0.50: X=__75___                   z = -2.00: X= ___60___ z = -1.50: X=_65____

4. For a population with a mean of μ = 40 and σ = 11, find the z–score for each of the foll52-40owing X values. (Note: You probably will need to use a formula and a calculator to find these values)

X = 45: z =_0.45___               X = 52: z =__1.09___           X = 41: z =__0.09___

X = 30: z =_-0.90____            X = 25: z =__-1.36___X = 38: z =___-0.18__

Answer 1