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Alice was told that her reading test score was 1 standard deviation below the mean. If test scores were approximately normal with μ=86 and σ=4, what was Alice's score? Do not include units in your answer. For example, if you found that the score was 86 points, you would enter 86.

User SanketR
by
6.5k points

2 Answers

3 votes

Answer:

it's 68

Explanation:

Alice was told that her reading test score was 1 standard deviation below the mean-example-1
User Toadflakz
by
6.0k points
3 votes

Answer:

82

Explanation:

Given that the population mean μ=86 and standard deviation σ=4 then one standard deviation below the mean means 4 less than 86 which is 82.

or

One standard deviation below the mean means z=-1 where z* is the z*score value in the standard normal distribution

Apply the formula

z=(x-μ)/σ

where x=Alice's score

μ=estimate mean

σ=standard deviation

z=(x-μ)/σ

-1=(x-86)/4----------------cross multiply

-1*4=x-86

-4=x-86

-4+86=x

82=x

User Pgl
by
6.4k points
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