In addition to mean and sample size you will need the individual scores.
The formula for standard deviation is:
S^2 = E(X-M)^2/N-1
Here's an example:
Data set: 4,4,3,1
Mean: 3
Sample size: 4
First, put the individual scores one after the other and subtract the mean from it.
4 - 3 = 1
4 - 3 = 1
3 - 3 = 0
1 - 3 = -2
Second, square the answers you got from step 1.
1^2 = 1
1^2 = 1
0^2 = 0
-2^2 = 4
Third, plug the values from step 2 into the formula.
S^2 = (1+1+0+4)/(4-1) = 6/3 = 2
Standard deviation = 2
Answer:
C. x+y = 1 and -x-y = -1
Step-by-step explanation:
Remember that if a system of equations has an infinite number of solutions, then the resulting equation from using the first step of the elimination method would have no variables and would be true.
1) Let's try canceling out the equations in option C, x+y =-1 and -x-y =-1. Add the two equations together. (Work shown in attached picture.)
2) All of the terms cancel out with each other, leaving only a true statement of 0 = 0. Thus, option C is the answer.
Answer:
80
Step-by-step explanation:
we search for a square number so that rows*plantsInARow gives us the number
The number should be around 50², guessed
50² = 2500 (to low)
51² = 2601 (still to low)
52² = 2704 (bingo)
now to get from 2624 to 2704 plants he needs 80 more. That is the least number.
He could also go to plant 60² plants an than need slot more.
(would really appreciate the brainliest)