A teacher wants to know how much she can predict a student's reading level from their grade level in a given school district. The table shows the grade and reading levels of eight students.
Missing Metadata
What percent of variation in the reading level can be explained by changes in the grade level?

74.7%

90.7%

82.4%

86.6%

Question

A teacher wants to know how much she can predict a student's reading level from their grade level in a given school district. The table shows the grade and reading levels of eight students.
   Missing Metadata   
What percent of variation in the reading level can be explained by changes in the grade level?
 
		
74.7%
		
90.7%
		
82.4%
		
86.6%

freemap · Answer

attachment

freemap · Answer

am I supposed to divide something

directrix · Answer

I think you will need to compute the coefficient of correlation and then use a formula to get the explained variation. Let me look up that formula.

freemap · Answer

Are you still looking up the formula

directrix · Answer

I found this. See attachment. Look in your text to see what is said about explained variation. http://www.csun.edu/~mr31841/documents/Varitionandpredictionintervals.pdf

freemap · Answer

I'm looking still

freemap · Answer

|dw:1456883803842:dw|

freemap · Answer

D

directrix · Answer

Let's go with that. I have been working but without success.

directrix · Answer

Frustrating. I am going to ask @kropot72 to help when he logs in.

freemap · Answer

Thanks for all your hard work that you put into this

kropot72 · Answer

The link given by @Directrix defines the coefficient of determination as follows:
$$\large Coefficient\ of\ determination=\frac{explained\ variation}{total\ variation}=r ^{2}$$
where r is the linear correlation coefficient.
If you find the value of r from the given data, square the result and convert the decimal value to a percentage, the correct choice of answer will be found.