Subtract original amount from new amount:
84 - 39 = 45
He bought 45 books.
1/3 + 2/9 equals 3/9
3/9 is then simplified to 1/3 :)
Using the z-distribution, the 99% confidence interval to estimate the population proportion is: (0.2364, 0.4836).
<h3>What is a confidence interval of proportions?</h3>
A confidence interval of proportions is given by:

In which:
is the sample proportion.
In this problem, we have a 99% confidence level, hence
, z is the value of Z that has a p-value of
, so the critical value is z = 2.575.
The estimate and the sample size are given by:
.
Then the bounds of the interval are:
The 99% confidence interval to estimate the population proportion is: (0.2364, 0.4836).
More can be learned about the z-distribution at brainly.com/question/25890103
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Answer:
100
Step-by-step explanation:
20%-10
20%*5=100%--10*5=100