Answer:
The cutoff sales level is 10.7436 millions of dollars
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean
and standard deviation
, the zscore of a measure X is given by:

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this problem, we have that:

15th percentile:
X when Z has a pvalue of 0.15. So X when Z = -1.047.




The cutoff sales level is 10.7436 millions of dollars
Weathering-the process of wearing or being worn by long exposure to the atmosphere.
1/16. that is the value that has the most x's on the graph.
945 rounded to the nearest ten is 950