Using the t-distribution, as we have the standard deviation for the sample, it is found that the 95% confidence interval for the number of units students in their college are enrolled in is (11.7, 12.7).
<h3>What is a t-distribution confidence interval?</h3>
The confidence interval is:

In which:
is the sample mean.
- s is the standard deviation for the sample.
The critical value, using a t-distribution calculator, for a two-tailed <em>95% confidence interval</em>, with 49 - 1 = <em>48 df</em>, is t = 2.0106.
Hence:


The 95% confidence interval for the number of units students in their college are enrolled in is (11.7, 12.7).
More can be learned about the t-distribution at brainly.com/question/16162795
D
Because if x=8 and y=3 then 3x and 8y are equal. So if we are trying to find an equal to 40y then you need to find what 40 times y equals first. So, 40x3=120. If we substitute x with 8 and multiply it with 15 then you get 120 so it’s equal.
Answer:
30ft²
Explanation:
The area of the plywood that she has:
8 ⋅ 9
=72ft²
The area of the plywood she cut
7 ⋅ 6
=42ft²
The area discarded should be:
72ft² - 42ft²
= 30ft²
4(4x+5y) this should be the right answer