Answer:
Chiara has 2 penny coins and 24 nickel coins
Step-by-step explanation:
Let
p ----> the number of penny coins
n ---> the number of nickel coins
Remember that


Chiara has 26 coins that equal 34 cents
so

isolate the variable x
----> equation A
34 cents=$0.34

Multiply by 100 both sides

isolate the variable x
-----> equation B
Create a table to guess
assume different values of n and determine the value of p in equation A and equation B
The solution is when the value of p in the equation A must be equal to the value of p in equation B
1) For n=1
equation A

equation B


2) For n=2
equation A

equation B

therefore
The solution is (2,24)
Chiara has 2 penny coins and 24 nickel coins
Answer:
-11
Step-by-step explanation:
Hope I helped
Answer:

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 = 20 - 1 = 19
99% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 19 degrees of freedom(y-axis) and a confidence level of
. So we have T = 2.861.
The margin of error is:

In which s is the standard deviation of the sample and n is the size of the sample.
The format of the confidence interval is:

In which
is the sample mean
So

Answer:
D. 100°
Step-by-step explanation:
A straight line is 180°. Add 50° and 30° (which is 80°) and subtract the total from 180°.
50 + 30 = 80
180 - 80 = 100
First blank: not random Because he sent it to the top 5 students. Not random students throughout the grade.
second blank: I would guess not valid because it was not a random sample.