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:
3.5
Step-by-step explanation:
This can be calculatdd by applyinthe g Pythagorean theorem
a^2 + b^2= c^2
12^2 + x^2= 12.5^2
144+ x^2= 156.25
x^2= 156.25-144
x^2= 12.25
x= √12.25
x= 3.5
Hence the distance between the ladder and the house is 3.5 ft
Because the ratio for both candles is 20/60 or 1/3 then take the number of ounces the candle has and divide by 1/3. In expression: 9 / 1/3 => 9 * 3 = 18
The roots of an equation are simply the x-intercepts of the equation.
See below for the proof that 
has at least two real roots
The equation is given as:
There are several ways to show that an equation has real roots, one of these ways is by using graphs.
See attachment for the graph of
Next, we count the x-intercepts of the graph (i.e. the points where the equation crosses the x-axis)
From the attached graph, we can see that crosses the x-axis at approximately <em>-2000 and 2000 </em>between the domain -2500 and 2500
This means that has at least two real roots
Read more about roots of an equation at:
brainly.com/question/12912962
