Answer:
a) y = 0.74x + 18.99; b) 80; c) r = 0.92, r² = 0.85; r² tells us that 85% of the variance in the dependent variable, the final average, is predictable from the independent variable, the first test score.
Step-by-step explanation:
For part a,
We first plot the data using a graphing calculator. We then run a linear regression on the data.
In the form y = ax + b, we get an a value that rounds to 0.74 and a b value that rounds to 18.99. This gives us the equation
y = 0.74x + 18.99.
For part b,
To find the final average of a student who made an 83 on the first test, we substitute 83 in place of x in our regression equation:
y = 0.74(83) + 18.99
y = 61.42 + 18.99 = 80.41
Rounded to the nearest percent, this is 80.
For part c,
The value of r is 0.92. This tells us that the line is a 92% fit for the data.
The value of r² is 0.85. This is the coefficient of determination; it tells us how much of the dependent variable can be predicted from the independent variable.
I assume the equation is
√(2x - 5) - √(x + 6) = 0
Note the domains for the root expressions:
• √(2x - 5) : 2x - 5 ≥ 0 ⇒ x ≥ 5/2
• √(x + 6) : x + 6 ≥ 0 ⇒ x ≥ -6
So any valid solution we find must be at least 5/2.
Move one term to the other side.
√(2x - 5) = √(x + 6)
Take squares.
(√(2x - 5))² = (√(x + 6))²
2x - 5 = x + 6
Solve for x :
x = 11
The answer should be 117.6. tell the teacher that the amount of meters is wrong or the answers are wrong
sorry :(
