It looks like you might have intended to say the roots are 7 + i and 5 - i, judging by the extra space between 7 and i.
The simplest polynomial with these characteristics would be
but seeing as each of the options appears to be a quartic polynomial, I suspect f(x) is also supposed to have only real coefficients. In that case, we need to pair up any complex root with its conjugate to "complete" f(x). We end up with
which appears to most closely resemble the third option. Upon expanding, we see f(x) does indeed have real coefficients:
3x² + 9x - 54 :(3)
x² + 3x - 18
(x-3)*(x+6)
Answer:
The standard deviation of the following data set is 32.2
Step-by-step explanation:
step 1
Find the mean
we have
![[56,78,123,34,67,9,20]](https://tex.z-dn.net/?f=%5B56%2C78%2C123%2C34%2C67%2C9%2C20%5D)
Sum the data and divided by the number of elements
![[56+78+123+34+67+91+20]/7=469/7=67](https://tex.z-dn.net/?f=%5B56%2B78%2B123%2B34%2B67%2B91%2B20%5D%2F7%3D469%2F7%3D67)
step 2
For each number: subtract the Mean and square the result
![[(56-67)^{2},(78-67)^{2},(123-67)^{2},(34-67)^{2},(67-67)^{2},(91-67)^{2},(20-67)^{2}]](https://tex.z-dn.net/?f=%5B%2856-67%29%5E%7B2%7D%2C%2878-67%29%5E%7B2%7D%2C%28123-67%29%5E%7B2%7D%2C%2834-67%29%5E%7B2%7D%2C%2867-67%29%5E%7B2%7D%2C%2891-67%29%5E%7B2%7D%2C%2820-67%29%5E%7B2%7D%5D)
![[121,121,3,136,1,089,0,576,2,209]](https://tex.z-dn.net/?f=%5B121%2C121%2C3%2C136%2C1%2C089%2C0%2C576%2C2%2C209%5D)
step 3
Work out the mean of those squared differences
![[121+121+3,136+1,089+0+576+2,209]/7=1,036](https://tex.z-dn.net/?f=%5B121%2B121%2B3%2C136%2B1%2C089%2B0%2B576%2B2%2C209%5D%2F7%3D1%2C036)
This value is called the "Variance"
step 4
Take the square root of the variance
Answer:320
Explanation:
20 days times 13 pages= 260pages
10 days times 6 pages = 60pages
Total for the 30 days:
260+60= 320 pages total
Graph those points given, in a cartesian plane grid,
that is, an x,y axis grid
and try to make a straight line from the leftmost, to
the rightmost, they don't really line up as a straight
line, so... try to draw a line that will cover "most of
the points", there will be a couple or so "outliers",
the line that "covers most of the points" is so-called
"best-fit" line, so, using that line, try to get what
"y" is, when x = 3
