Since the mean of Exam A is 300 and the standard deviation is 25, Aira scored 1 standard deviation above the mean. This means
[tex]\begin{gathered} \bar{x}+\sigma=x \\ 300+25=325 \end{gathered}[/tex]
To do equivalently well in Exam B, Aira must also obtain a score of 1 standard deviation above the mean of Exam B. Thus, add the standard deviation of 10 to the mean of 51.
[tex]\begin{gathered} \bar{x}+\sigma=x \\ 51+10=61 \end{gathered}[/tex]
Thus, she needs to have a score of 61 in Exam B.
