Answer:
We have strong evidence that on average, students study less than 150 minutes per night during the school week
Step-by-step explanation:
Normal distribution:
mean μ₀ = 150
Sample:
Sample size n = 272
Sample mean x = 141
Sample standard deviation s = 66
The standard error of the sample mean SE = σ /√n
SE = 66/√272
SE = 66 / 16,49
SE = 4
Test Hypothesis:
Null hypothesis H₀ x = μ₀
Alternative hypothesis Hₐ x < μ₀
z(s) test statistics is:
z(s) = ( x - μ₀ ) / s/√n
z(s) = - 9 /4
z(s) = - 2,25
p-value for that z(s) p-value = 0,0122
Then for α = 0,05 p-value < 0,05
We are in the rejection region we need to reject H₀
This is the correct answer: 3x^3 - x^2 + 6x - 9
If we identify the lines by ...
1. y = -0.5x -3
2. y = -3.5x -15
3. y = 5x +19
4. y = 1.25x +4
Then the matches are ...
BC - 2
DE - 1
FG - none
HI - 4
JK - none
LM - 3
_____
Whenever there is a lot of repetitive math to do, I usually find it easier to let a calculator or spreadsheet do it. Here, the graphing calculator is computing the slope between the points. The slopes of parallel lines are the same.
The error is when she added 4 to both sides.
Instead, she should divide both sides by -4 to undo the multiplication. Specifically, the multiplication between the -4 term and the (x-2)^2 term.
This is one possible correction of what her steps could look like.

In the third step, I'm dividing both sides by -4. In the sixth step, I'm applying the square root to both sides to undo the squaring operation. Then two steps later, I'm adding 2 to both sides to undo the "-2", which helps fully isolate x.
The only solution is x = 2, so it's the only x intercept. You can verify this answer by plugging x = 2 back into the original equation at the very top. You should end up with y = 0.
Note: The term "root" is another name for "x intercept".