Given a mean = 1300 and a Ď = 200, we can calculate that the lower bound of 1000 is (1000 - 1300) / 200 = -1.5 standard deviations below the mean.
The upper bound is (1437 - 1300) / 200 = 0.685 standard deviations from the mean.
Using the cumulative distribution function, we can calculate that the probability a randomly chosen steer lies on the interval [1000, 1437] is CDF(0.685) - CDF(-1.5) = 0.68652083824480004
p = 0.6865
