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Vince's 2011 act reading score was below 33% of all the scores. if the mean and standard deviation for all act reading scores in 2011 were 21.3 and 6.2 respectively, what was vince's score?

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toporc
The z-score corresponding to a cumulative probability of 0.33 is -0.44.
Let X be the score just above Vince's highest possible score.
The required formula is:
[tex]z=\frac{X-\mu}{\sigma}[/tex]
Plugging the given values into the formula, we get:
[tex]-0.44=\frac{X-21.3}{6.2}[/tex]
Solving for X, gives X = 18.572.
Therefore Vince's score < 18.572.