Mrs. blair believes there is a relationship between the number of minutes students study and their test grades. she asked her history class to list the number of minutes they studied and their test grade. using the information provided draw a scatterplot. what test grade might a student expect if they studied approximately 95 minutes?
x + y
a) 60
b) 80
c) 100
d) 120
minutes studying test grade
20 65
22 65
25 50
25 52
30 55
30 68
45 70
45 69
60 75
75 80
90 78
90 83
90 85
100 88
100 78
110 95
120 96
120 100
150 91
150 85
160 82
180 80
180 80

B) 80  

Step-by-step explanation:

In the figure attached, the scatter plot is shown.

If you make a linear regression of data (I made it Excel, you can also use a calculator) you will get the following equation:

y = 0.1893*x + 60.355

where y is Test grade and x is Minutes studying. Replacing with x = 95, we get:

0.1893*95 + 60.355 ≈ 80

hello from mrbilldoesmath!

answer:

a(n) - a(n-1) -3

discussion:

this ones a bit interesting. given a(n) = 5 - 3n consider this:

a(n-1) = 5 - 3(n-1)

          = (5 - 3n) + 3             => but a(n) = 5 - 3n, the first term

          = a(n)   + 3                 => subtract 3 from both sides

a(n-1) -3 = a(n)  

or

a(n) - a(n-1) -3

you,

mrb

step-by-step explanation:

there is a formula i can give you:

it is r^2*n*sin(360/n) divided by 2 where r represents the "radius" and n is the number of sides.

plug them in:

(10sqrt(3))^2*6*sin(360/6) divided by 2

100*3*6*sin(60) divided by 2

900*sin(60)

900*sqrt(3)/2

450*sqrt(3)

approx is 779.4 cm^2