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3 years ago

Find the standard deviation if the mean of a sample is 72, a z-score of 3 Raw Score: 42 Raw Score: 81

Mathematics

1 answer:

Fynjy0 [20]3 years ago

6 0

Answer:

a) when x = Raw Score: 42

Standard deviation = σ = -10.3

b) Raw Score: 81

Standard deviation = σ = 2.67

Step-by-step explanation:

Find the standard deviation if the mean of a sample is 72, a z-score of 3

Z score formula is given :

z = (x-μ)/σ,

where

x is the raw score

μ is the population mean = 73

σ is the population standard deviation

z = 3

a) when x = Raw Score: 42

z = (x-μ)/σ

3 = 42 - 73/σ

Cross Multiply

3σ = 42 - 73

3σ = -31

σ = -31/3

σ = -10.3

b) Raw Score: 81

z = (x-μ)/σ

3 = 81 - 73/σ

Cross Multiply

3σ = 81 - 73

3σ = 8

σ = 8/3

σ = 2.67

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