Answer:
<em>There are 12 boys and 18 girls</em>
Step-by-step explanation:
<u>Equations</u>
There are 30 students in a class. Let's call:
x = number of boys
Since the sum of boys and girls is 30:
30 - x = number of girls
The ratio of boys to girls is 2:3, thus:
Crossing denominators:
3x = 2(30 - x)
Operating the parentheses:
3x = 60 - 2x
Adding 2x:
5x = 60
Dividing by 5:
x = 60/5 = 12
x = 12
There are 12 boys and 30-12=18 girls
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:
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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