Question

The width of a triangle is 6 cm less than its length. If its perimeter is 80 cm then its lengths (in cm) and area (in cm²) are respectively
A) 16,351
B) 23,391
C) 17,391
D) 20,341
E) None

Answer 1

i spose the key to this is in determining how to find a standard deviation.

Answer 2

if we know the mean of a set of numbers, then the average of the square of the difference from the mean define variation, and sqrt(variation) = stand dev

Answer 3

(a-20)^2 + (b-20)^2
------------------ = 5^2
2

Answer 4

First of all the AM of 5, 15 is not 20, so we are left with the other options.

Answer 5

http://www.mathsisfun.com/data/standard-deviation-calculator.html