An unknown distribution has a mean of 90 and a standard deviation of 15. A sample of size 64 is randomly drawn from the population.

Given these formulas:

_{= (n) (x) = mean of}

_{= () (x) = standard deviation of}

_{= (n) (x) + (z) () (x)}

Find the sum that is 1.2 standard deviations below the mean of sums.