Answer: A. 85.7
Step-by-step explanation:
Given : Two sections of a class took the same quiz.
Section A had 15 students who had a mean score of 80, and Section B had 20 students who had a mean score of 90.
We know that , 
Then , for section A :


Similarly in Section B, 
Total scores = Sum of scores in sec A+Sum of scores in sec B
=1200+1800=3000
Total students = Students in sec A +Students in sec B
=15+20=35
Now , the mean score for all of the students on the quiz =

Hence, the approximate mean score for all of the students on the quiz = 85.7
Thus , the correct answer is option A. 85.7.
Answer:
There is no solution to the system in its original form. There are no points in common. If the signs are reversed, the solution has an intersection with an infinite number of solutions.
Step-by-step explanation:
Its right on edg
Following PEMDAS is crucial to solving these. Please Excuse My Dear Aunt Sally
P - Parenthesis
E - Exponents
M - Multiplication
D - Division
A - Addition
S - Subtraction
Multiplication/Division and Addition/Subtraction are interchangeable.
Now then, number 1 has the following:

There are no parenthesis or exponents, but there is multiplication, so we will start with multiplying. There are two multiplication expressions in the problem.


Since you did that, your answer has been simplified to:

Now, all you have to do is combine your like terms. Since every term is alike, you can combine the whole expression.

So, your final answer would be:

Hopefully with this information, you can solve the rest. If you have any questions, let me know.
Answer:
choosing two socks from a drawer of black and white socks without replacement
Step-by-step explanation:
Dependent events have results that depend on each other. When I take one sock out, there are less socks in the drawer to pick from. The probability of picking a certain sock changes because the number of socks are different when I do not put the sock back. That makes the events dependent.
When I put the sock back, the probability goes back to what it was before I took the sock, and now the results do not depend on each other, so when they are replaced, they are independent
No she didn't write it correct.
it is soppose to be like this 72,506.
seventy-two thousand five hundred and six