We have that
set of data [<span>8, 12, 15, 17, 18]
step 1
Find the mean
</span>[8+ 12 + 15 + 17 + 18]/5-------> 70/5------> 14
step 2
for each number: subtract the Mean and square the result
(8-14)²----->36
(12-14)²----> 4
(15-14)²----> 1
(17-14)²----> 9
(18-14)²----> 16
step 3
<span> work out the mean of those squared differences
[36+4+1+9+16]/5-----> 66/5-----> 13.2----> </span><span>this value is called the "Variance"
step 4
</span><span>Take the square root of that
</span>standard desviation=√13.2-----> 3.63-------> 4
the answer is
4
2.40
5.40-2.40= 3 (price of 2 sodas)
8.70 - 7.20 = 1.5 (price of 1 soda)
The soda prices match up so a hamburger is 2.40
Answer:
A) x^2 + 2x+ y^2 - 4y + z^2 - 2z - 63 = 0
B) radius = 5
center = (4,-1,-3)
Step-by-step explanation:

A ) Determine the curve in which the sphere intersects the yz-plane
determine the radius ( r ) = √((6-(-1))2+(-2-2)2+(3-1)2) = √69
next the equation of the sphere ( curve in which the sphere intersects the yz-plane )
x^2+2x+y^2-4y+z^2-2z-63 = 0
B) determine the center and radius of the sphere
X^2 + y^2 + z^2 -8x + 2y +6z + 1 = 0
(x-4)2+(y+1)2+(z+3)2 = 25 = 52
radius = 5
center = (4,-1,-3)