Answer:
The minimum income level for this target group is of $51,253.6.
Step-by-step explanation:
Normal Probability Distribution
Problems of normal distributions can be solved using the z-score formula.
In a set with mean
and standard deviation
, the z-score 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 p-value, we get the probability that the value of the measure is greater than X.
Mean of $41,182 and a standard deviation of $11,990
This means that 
Find the minimum income level for this target group.
The 100 - 20 = 80th percentile, which is X when Z has a p-value of 0.8, so X when Z = 0.84.




The minimum income level for this target group is of $51,253.6.