Here’s the full solution:
(Please mark as BRAINLIEST that would mean a lot to me)
Answer:
0.5981 = 59.81% probability that three or less of the selected adults have saved nothing for retirement
Step-by-step explanation:
For each adult, there are only two possible outcomes. Either they save nothing for retirement, or they save something. The probability of an adult saving nothing for retirement is independent of any other adult. This means that the binomial probability distribution is used to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which
is the number of different combinations of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.
20% of adults in the United States save nothing for retirement (CNBC website).
This means that 
Suppose that sixteen adults in the United States are selected randomly.
This means that 
What is the probability that three or less of the selected adults have saved nothing for retirement?
This is:

In which






0.5981 = 59.81% probability that three or less of the selected adults have saved nothing for retirement
the solution is where the line cross on the y axis, which is on 0
so y = 0
First, the formula for the average of a data set must be defined. It is calculated by adding all the numbers in the data set and then dividing the sum by the number of data. In this case, the average is set to be equal to $400 with the total number of data being 3, with the September expenditure set as an unknown, x. The equation is then set-up to be: 400 = (401.5 + 250 + x)/3. Thus, Joshua can spend as much as $ 548.5 to be able to have the same average as in his second quarter expenditure.