Using the empirical rule for a normal distribution. the required interval is within plus and minus two standard deviations from the mean: 62.5 - 36 = 26.5. 62.5 + 36 = 98.5. The interval is (26.5, 98.5).
The empirical rule states that in a normal distribution, 68% of data fall within one standard deviation of the mean; 95% of data fall within two standard deviations of the mean; and 99.7% of data fall within three standard deviations of the mean.
Since we want 95% of the data, that means our data will fall within 2 standard deviations. Since the standard deviation is 18, two standard deviations will be 2*18 = 36.
Two standard deviations below the mean will be 62.5-36 = 26.5.
Two standard deviations above the mean will be 62.5+36 = 98.5.
