(I'm not totally sure but there may be someone else with a more accurate/correct answer.)
Here is what I got (Red represents my work, blue represents to follow which steps and highlighter represents what the answer is):
Answer:
Step-by-step explanation:
we know that
<em>Joey can paint a room in 2 hours</em>
That means
Joey can paint the 100% of the room-------> 2 hours
so
In 1 hour ------> can paint 100%/2=50%
<em>Chelsea can paint a room in 3 hours</em>
That means
C<em>helsea</em> can paint the 100% of the room-------> 3 hours
so
In 1 hour ------> can paint (100%/3)=33.33%
therefore
Joey and Chelsea in 1 hour can paint -----> 50%+33.33%=83.33%
by proportion
Answer:
Step-by-step explanation:
Given
Solving (a): Mean
Solving (b): Standard Deviation (SD)
From (1), we get x = (8 - 3y) / 2 ––(3)
Substitute (3) into (2),
2 [(8 - 3y) / 2]² + 3y² = 110
(8 - 3y)² + 3y² = 220
15y² - 48y - 156 = 0
Therefore y = 5.2, then x = (8 - 3×5.2) / 2 = -3.8
OR y = -2, then x = [8 - 3×(-2)] / 2 = 7
The cordinates of A and B are (-3.8, 5.2) and (7, -2).
