Answer:
254 4/7 or 254.34 ft² (it depends on which method you use.)
Step-by-step explanation:
To find the area of a circle, the formula is πr².
I'll use both 22/7 and 3.14 as pi, so I'll end up with two different answers. Just choose the more reliable one.
22/7 version:
22/7 * 9^2
22/7 * 81/1
1782/7
254 4/7 ft²
3.14 version:
3.14 * 9^2
3.14 * 81
314 - (3.14 * 19)
314 - 62.8 + 3.14
251.2 + 3.14
254.34 ft²
As I said, I ended up with two different answers. You also had said not to round my answer, so the 22/7 version has a mixed number.
Answer:
$3
Step-by-step explanation:
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.
