Answer:
24.25
Step-by-step explanation:
The minimum admission score is at the 70th percentile of the normal distribution which, according to a z-score table, corresponds to a z-score of 0.524.
The z-score, for any given value X, is determined by:
[tex]z=\frac{X-\mu}{\sigma}[/tex]
If the mean score is 21 and the standard distribution is 6.2, the minimum required score for admission is:
[tex]0.524=\frac{X-21}{6.2}\\X=24.25[/tex]
The minimum score required for admission is 24.25.