You can make a proportion of 8/20 to 42/x and then simply cross multiply from there to solve for y
Answer:
2 
Step-by-step explanation:
Change the mixed numbers to improper fractions
(
-
) +
← the LCM of 2 and 3 is 6
=
-
+ 
=
-
+ 
=
+ 
= 
= 
= 2 
Using the z-distribution, it is found that the lower bound of the 99% confidence interval is given by:
d. 68.39%.
<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 sample size and estimate are given by:

Hence, the lower bound is given by:

Hence the lower bound is of 68.39%, which means that option D is correct.
More can be learned about the z-distribution at brainly.com/question/25890103
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Yes, by 0.001. Thank me later.