Answer:
A. R2 = 0.6724, meaning 67.24% of the total variation in test scores can be explained by the least‑squares regression line.
Step-by-step explanation:
John is predicting test scores of students on the basis of their home work averages and he get the following regression equation
y=0.2 x +82.
Here, dependent variable y is the test scores and independent variable x is home averages because test scores are predicted on the basis of home work averages.
The coefficient of determination R² indicates the explained variability of dependent variable due to its linear relationship with independent variable.
We are given that correlation coefficient r= 0.82.
coefficient of determination R²=0.82²=0.6724 or 67.24%.
Thus, we can say that 67.24% of total variability in test scores is explained by its linear relationship with homework averages.
Also, we can say that, R2 = 0.6724, meaning 67.24% of the total variation in test scores can be explained by the least‑squares regression line.
The fraction would be 17/100
Answer:
<em>630 cups</em>
Step-by-step explanation:
<u>Percentages</u>
This problem is most easily solved backward, i.e., from the final data up to the beginning.
There was a new box of cups and the worker at a snack stand opened it. He first used 30 cups from the box and the second day he uses 15% of the remaining cups in the box, and we are told that represents 90 cups.
If 15% (0.15) equals 90 cups, then the number of cups before the second day was 90/0.15 = 600 cups.
On the first day, we used 30 cups, thus the original number of cups in the box was 600+30=630 cups
Rearrange the equation by subtracting what is to the right of the equal sign from both sides of the equation :
7*x-4-(21)=0
Solve : 7x-25 = 0
Add 25 to both sides of the equation :
7x = 25
Divide both sides of the equation by 7:
x = 25/7 = 3.571
Answer:
x
=
3
,
−
8
Step-by-step explanation:
