I think that this is just showing how you can make different percentages by multiplying/dividing by specific numbers.
Answer: 60
Step-by-step explanation: I did the math but sorry if this is wrong
P = 2a + b
10= 2a + 3
2a = 10-3
a = 7/2 = 3.5
Therefore, numerical value of a is 3.5
Using the z-distribution, it is found that the 90% confidence interval is given by: (0.6350, 0.6984).
<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 90% confidence level, hence
, z is the value of Z that has a p-value of
, so the critical value is z = 1.645.
The sample size and the estimate are given by:

Hence, the bounds of the interval are given by:


The 90% confidence interval is given by: (0.6350, 0.6984).
More can be learned about the z-distribution at brainly.com/question/25890103
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P=3 and p=-1
First you subtract the number without a variable to the other side, so subtract one from seven, and subtract five from eight. After that just divide to make p by its self and you get the answer!!