In which set of points is y not a function of x? {(-4,-4), (-3, -3), (-2,-2), (-1, -2)}
{(4,-4), (3, -3), (3, -2), (1, -1)}
O {(-4,4),(-3, 3), (-2, 2), (-1, 1)}
O {(4,4), (3, 3), (2, 2), (1, 1)}

the first one because when x=-1 y=-2 and that does not directly vary with x

Step-by-step explanation:

1) The best estimate for the average cost of tuition at a 4-year institution starting in 2020 =$ 31524.31

2) The slope of regression line b=937.97 represents the rate of change of  average annual cost of tuition at 4-year institutions (y) from 2003 to 2010(x).  Here,average annual cost of tuition at 4-year institutions is dependent on school years .

Step-by-step explanation:

1) For the given situation we need to find linear regression equation Y=a+bX for the given situation.

Let x be the number of years starting with 2003 to 2010.

i.e. n=8

and y be the average annual cost of tuition at 4-year institutions from 2003 to 2010.  

With reference to table we get

By using above values find a and b for Y=a+bX, where b is the slope of regression line.

and

∴ To find average cost of tuition at a 4-year institution starting in 2020.(as n becomes 18 for year 2020 if starts from 2003 ⇒X=18)

So, Y= 14640.85 + 937.97×18 = 31524.31

∴The best estimate for the average cost of tuition at a 4-year institution starting in 2020 = $31524.31