It’s the light blue one!!!
Average reading score is given by the expression,
y = 0.153x + 255.4
Here, x in the number of years past 1970.
To find the year in which the average reading score is 259.378, substitute the value of 'y' in the given expression.
y = 0.153x + 255.4
259.378 = 0.153(x) + 255.4
0.153x = 259.378 - 255.4
0.153x = 3.978
x = 
x = 26
That means given average reading score 259.378 will be 26 years after 1970.
Therefore, 1996 is the year in which the average reading score will be 259.378.
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brainly.com/question/2883790
If a = first term and r = common ratio we have
a + ar + ar^2 = 13 and ar^2 / a = r^2 = 9
so r = 3
and a + 3a + 9a = 13
so a = 1
so they are 1,3 and 9
2.
in geometric series we have
4 , 4r ,4r^2 , 60
Arithmetic;
4, 4r , 4r + d , 4r + 2d
so we have the system of equations
4r + 2d = 60
4r^2 = 4r + d
From first equation
2r + d = 30
so d = 30 - 2r
Substitute for d in second equation:-
4r^2 - 4r - (30-2r) = 0
4r^2 - 2r - 30 =0
2r^2 - r - 15 = 0
(r - 3)(2r + 5) = 0
r = 3 or -2.5
r must be positive so its = 3
and d = 30 - 2(3) = 24
and the numbers are 4*3 = 12 , 4*3^2 = 36
first 3 are 4 , 12 and 36 ( in geometric)
and last 3 are 12, 36 and 60 ( in arithmetic)
The 2 numbers we ause are 12 and 36.
