Answer:
The 99% confidence interval is (3.0493, 3.4907).
We are 99% sure that the true mean of the students Perry score is in the above interval.
Step-by-step explanation:
Our sample size is 21.
The first step to solve this problem is finding our degrees of freedom, that is, the sample size subtracted by 1. So
.
Then, we need to subtract one by the confidence level 
and divide by 2. So:
Now, we need our answers from both steps above to find a value T in the t-distribution table. So, with 20 and 0.005 in the two-sided t-distribution table, we have 
Now, we find the standard deviation of the sample. This is the division of the standard deviation by the square root of the sample size. So
Now, we multiply T and s
Then
The lower end of the interval is the mean subtracted by M. So:
The upper end of the interval is the mean added to M. So:
The 99% confidence interval is (3.0493, 3.4907).
Interpretation:
We are 99% sure that the true mean of the students Perry score is in the above interval.
After plotting all the three points, we get the parabolic equation in the form is 2(x - 1)²-34.
<h3>What is parabola?</h3>
Any point on a parabola, which has the shape of a U, is situated at an equal distance from the focus, a fixed point, and the directrix, a fixed line.
General equation of the quadratic equation,
Y = ax² + bx +c
Given points,
(-2, 0),
(-1, -10),
(4, 0).
Putting the points in the general equation,
Putting (-2, 0), we get
0 = 4a - 2b + c
Putting (-1, -10), we get
-10 = a - b +c
Putting (4, 0), we get
0 = 16a + 4b +c
Solving all equations we get,
a = 2 , b = -4 , c = -16
After putting the values,
Y = 2x²- 4x- 16
2(x² - 2x - 8)
2(x²- 2x + 1 - 1 - 16)
=2(x - 1)²-34
Hence we get the required equation in the parabolic form.
To know more about parabola, visit :
brainly.com/question/21685473
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Answer:right and scalene I think
Step-by-step explanation:
Answer:
72/4=18 so she could make their lunch for 18 days
Step-by-step explanation:
so it would be 6x12 for the bagels which would be 72
for the apples it would be 8x9 which is 72
the cookies would be 12x6 to get 72
and the juice boxes would be 9x8 to get 72
divide that by 4 to get 18
