I need some help so I can bring my grade up. More than one answer
( if you don't know don't answer )
( you will get reported for absurd answers )
( 20 points + brainlist )
SCIENCE

Describe in detail how you would construct a 95% confidence interval for a set of 30 data points whose mean is 20 and population standard deviation is 3. be sure to show that you know the formula and how to plug into it. also, clearly state the margin of error.

Determine the number of girls in a math class with 87 boys if there are 25 girls for every 75 boys

Two corresponding sides of two similar triangles are 3cm and 5cm. the area of the first triangle is 12cm2. what is the area of the second triangle?