Answer:
The 90% confidence interval for the mean test score is between 77.29 and 85.71.
Step-by-step explanation:
We have the standard deviation for the sample, so we use the t-distribution to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 25 - 1 = 24
90% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 24 degrees of freedom(y-axis) and a confidence level of
. So we have T = 2.064
The margin of error is:

In which s is the standard deviation of the sample and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 81.5 - 4.21 = 77.29
The upper end of the interval is the sample mean added to M. So it is 81.5 + 4.21 = 85.71.
The 90% confidence interval for the mean test score is between 77.29 and 85.71.
Explanation is in a file
bit.
ly/3a8Nt8n
They are both equal I think C.
Answer:
<h2>
35°</h2>
Step-by-step explanation:
This is an isoceles triangle
And as we all know an isoceles triangle has two equal base angles.
And we also know that the sum of all interior angles of the triangle is 180°
So based on this we can form an algebraic equation of solve for angke t (Let's do it :))

So the base angle is 35°