# Khan/khan-exercises

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 Z scores 1
randRange( 65, 85 ) randRange( 2, 5 ) + randRange( 0, 1 ) * 0.5 randRangeWeighted( roundTo( 0, MEAN - STDDEV * 3 ), min( roundTo( 0, MEAN + STDDEV * 3 ), 100 ), MEAN, 0 ) roundTo( 2, ( GRADE - MEAN ) / STDDEV ) localeToFixed(ZSCORE, 2)
The grades on a course( 1 ) midterm at school( 1 ) are normally distributed with \mu = MEAN and \sigma = localeToFixed(STDDEV, 1).
person( 1 ) scored GRADE on the exam.

Find the z-score for person( 1 )'s exam grade. Round to two decimal places.

(GRADE - MEAN) /STDDEV

A z-score is defined as the number of standard deviations a specific point is away from the mean.

\large{\quad z \quad = \quad \dfrac{GRADE - \pink{MEAN}}{\green{localeToFixed(STDDEV, 1)}}}

\large{\quad z \quad \approx \quad SOLUTION}

The z-score is localeToFixed(ZSCORE, 2). In other words, person(1)'s score was SOLUTION standard deviation above the mean. In other words, person(1)'s score was SOLUTION standard deviation below the mean. In other words, person(1)'s score was SOLUTION standard deviations above the mean. In other words, person(1)'s score was SOLUTION standard deviations below the mean.