Answer:
66
Step-by-step explanation:
Use the formula:
\(X = \text{mean} + (\text{number of standard deviations} \times \text{standard deviation})\).
Substituting the given values, we get:
\(X = 51 + (3 \times 5) = 51 + 15 = 66\).
Therefore, the score that is 3 standard deviations above the mean is 66.