Answer:
If a certain cone with a height of 9 inches has volume V = 3πx2 + 42πx + 147π, what is the cone’s radius r in terms of x?
Step-by-step explanation:
V = 3πx2 + 42πx + 147π
V=3π(x2 + 14x +49)
9.42(x2 + 14x +49)
9.42(x2 + 14x +14) -14 + 49= 0
9.42(x + 7)^2 + 35= 0
9.42(9.42(x + 7)^2 = - 35)9.42
(x + 7)^2 = - 35/9.42)
√(x + 7)^2=√- 35/9.42
x + 7 = - 1.927
x= - 1.927 - 7
x= - 8.927
V = 3π(- 8.927)^2 + 42π(- 8.927) + 147π
V=750.69 - 1177.29 + 461.58
<u>V=34.98</u>
h= 9 inches
V = 13πr2h
34.98 = 13(3.14) (r^2) (h)
34.98 = 40.82 (r^2) 9
34.98 = 367.38 r^2
34.98/ 367.38 = 367.38 r^2/ 367.38
0.095= r^2
Answer:
54=12+r
Step-by-step explanation:
'Sum' means to add.
The slope of the line of best fit to the raw-score scatter plot is 0.98
- The equation is y = 0.98x - 3.74
- The value of y given that x = 12 is 8.02
<h3>How to determine the slope of the line?</h3>
From the question, we have the following parameters that can be used in our computation:
- Standard deviations of X, Sx = 1.88
- Standard deviations of Y, Sy =2.45
- Correlation coefficient, r between X and Y = 0.75
The slope (b) of the line is calculated as
b = r * Sy/Sx
Substitute the known values in the above equation, so, we have the following representation
b = 0.75 * 2.45/1.88
Evaluate
b = 0.98
<h3>The equation of the line of best fit</h3>
A linear equation is represented as
y = bx + c
Where
Slope = b
y-intercept = c
In (a), we have
b = 0.98
So, we have
y = 0.98x + c
Recall that the point (13, 9) is on the line of best fit.
So, we have
9 = 0.98 * 13 + c
This gives
9 = 12.74 + c
Evaluate
c = -3.74
So, we have
y = 0.98x - 3.74
<h3>The value of y from x</h3>
Here, we have
x = 12
So, we have
y = 0.98 x 12 - 3.74
Evaluate
y = 8.02
Read more about line of best fit at
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The anser i got was 3.33333 but i think you would plot it as 3.25