X = (15 - 8y)/9
-5[(15 - 8y)/9] + 12y = -107
(-75/9) + (40/9) + 12y = -107
y = -8.59
x = [15 - 8(-8.59)]/9
x = 9.3
(x,y) = (9.3, -8.59)
Answer:
Solve for a
a12−3(a−1)=11+a
Write the problem as a mathematical expression.
a12−3(a−1)=11+a
Simplify each term.
a12−3a+3=11+a
Graph each side of the equation. The solution is the x-value of the point of intersection.
a≈−1.1114621,1.23792371
Step-by-step explanation:
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
