80%
Ummm bro the explanation is simple he keeps 8/10 and he saves 2/10 sooo
8/10 x 10 = 80/100 spends 80%
2/10 x 10 = 20/100 saves 20%
Easy peasy...
Answer:
the first four
Step-by-step explanation:
The last two do not equal 9 or .90
Using the z-distribution, as we have the standard deviation for the population, it is found that the smallest sample size required to obtain the desired margin of error is of 77.
<h3>What is a z-distribution confidence interval?</h3>
The confidence interval is:

In which:
is the sample mean.
is the standard deviation for the population.
The margin of error is given by:

In this problem, we have that the parameters are given as follows:
.
Hence, solving for n, we find the sample size.






Rounding up, the smallest sample size required to obtain the desired margin of error is of 77.
More can be learned about the z-distribution at brainly.com/question/25890103
a = bx + cx + d Subtract d from both sides
a - d = bx + cx Factor x from bx and cx
a - d = x (b + c) Divide both sides by (b + c)

= x Switch the sides to make it easier to read
x = <span>

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