Mean, Median and Mode
Question
A test is administered annually. The test has a mean score of 150 and a standard deviation of 20. If Ravi’s z-score is 1.50, what was his score on the test?
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Statistics
55 years
2 Answers
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Contributor 1
Answers ( 2 )
From the formula,
X= μ+Zσ
where μ is the mean
σ is the standard deviation
X is the score we’re calculating
Therefore X = 150+20*1.5 = 180
Thus, his score was 180
Z value = (X-μ)/σ
X = Zσ + μ
Where μ is the sample mean and σ standard deviation
X = 1.5*20+150 = 180
so the test score is 180