Answer:
53
Step-by-step explanation:
Answer:
At least 202.44 mm in the top 15%.
Step-by-step explanation:
When the distribution is normal, we use 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 question, we have that:

How many yearly mm of rainfall would there be in the top 15%?
At least X mm.
X is the 100-15 = 85th percentile, which is X when Z has a pvalue of 0.85. So X when Z = 1.037.




At least 202.44 mm in the top 15%.
Plug in 12 for y and rewrite the equation.
12 = 4x + 4
Subtract 4 from both sides.
8 = 4x
Divide by 4 on both sides.
2 = x
The ordered pair is (2, 12) and x = 2.
My answer may not be correct but I feel pretty confident. The answer is $549.08