Since the standard deviation is 10 and the first given score is 40, the 40 is 2 standard deviations below the mean.
On the other hand, 80 is 2 standard deviations above the mean.
Thus, we subtract the probability below the z-score which is 2, 0.97725, and the probability below the z-score which is -2, 0.02275.
[tex]\begin{gathered} P(X)=0.97725-0.02275 \\ P(X)=0.9545 \end{gathered}[/tex]
We may obtain the values using the z-score table.
Therefore, the approximate value of the probability is 0.955.
