We have been given that the standard deviation of a group of 20 scores is 15 and we are asked to find variance.
Since we know variance is square of standard deviation. In order to find out the variance of the given data we have to take the square of 15.

Therefore, our variance is 225.
Yes I think it’s s right triangle
Answer:
<h2>
$400</h2>
Step-by-step explanation:
Using the formula for calculating the simple interest expressed as;
Simple Interest = Principal * rate * time/100
Note that the principal is the amount he originally borrowed
I = PRT/100 ............ 1
Amount paid off A = Principal+Interest
A = P+I ............ 2
From equation 2; I = A-P......... 3
Substitute equation 3 into 1;
A-P = PRT/100
Given A = $440, R = 10%, Time = 1year
Substitute the given parameters into the resulting equation;
440 - P = P*10*1/100
440-P = 10P/100
440-P = 0.1P
440 = 0.1P+P
440 = 1.1P
Divide through by 1.1;
1.1P/1.1 = 440/1.1
P = $400
<em>Hence the amount Mr Noel originally borrow is $400</em>
Earlier price is 2.80
Current price is 2.87
Increment is
2.87 - 2.80
0.07
Increment percentage is
(0.07 / 2.80) * 100
2.5 %
The answer is the last one 7/8 x -3/4 =6