Using the t-distribution to build the 99% confidence interval, it is found that:
- The margin of error is of 3.64.
- The 99% confidence interval for the population mean is (19.36, 26.64).
<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 95% confidence interval, with 21 - 1 = 20 df, is t = 2.086.
The other parameters are given as follows:

The margin of error is given by:

Hence the bounds of the interval are:


The 99% confidence interval for the population mean is (19.36, 26.64).
More can be learned about the t-distribution at brainly.com/question/16162795
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Answer:
9t^3 +t^2
Step-by-step explanation:
The perimeter of the figure is the sum of the lengths of the sides. The side lengths are represented by the polynomials shown, so the perimeter (P) is their sum:
P = (4t^3 -5) + (4t^3 -5) + (t^2 +9) + (t^3 -t^2 -11) + (t^2 +12)
Rearranging to group like terms:
P = (4t^3 +4t^3 +t^3) + (t^2 -t^2 +t^2) + (-5 -5 +9 -11 +12)
P = 9t^3 +t^2
The perimeter of the figure is represented by the polynomial 9t^3 +t^2.
Answer:

Step-by-step explanation:
We are given an expression and are asked to find what it equals. We can see that the two square roots are being multiplied, therefore they follow the same standard as any multiplication problem, do as followed :


Since a square root and constant number are different terms, we cannot combine them together, therefore leave as is :

104/-120
=-13/15
Devishri1977 gave a better example of how she got to the answer
First no. = x
Second no. = y
Equation Formation
x + y = 6..........equation(i)
x - y = 10...........equation (ii)
x = 6 - y
6 - y - y = 10
6 - 2 y = 10
-2 y = 10 -6
-2 y = 4
y = -2
x = 6 + 2
x = 8
Answer = 8 , -2