Here is my work. Hope it helps.
Answer: A. 6.5
Step-by-step explanation:
Here, the given set = { 15, 19 3, 12, 17, 2, 2, 8}
Mean, 
Number of elements, n = 8
Thus, the standard deviation, 
⇒ Option A is correct.
Answer:
B
Step-by-step explanation:
Givens
a^2 + b^2 = c^2
a = 4x
b = x + 2
c = 3x + 4
Solution
(4x)^2 + (x + 2)^2 = (3x + 4)^3 Remove all the brackets.
16x^2 + x^2 + 4x + 4 = 9x^2 + 24x + 16 Collect like terms on the left
17x^2 + 4x + 4 = 9x^2 + 24x + 16 Subtract the terms on the right
8x^2 - 20x - 12 = 0
This factors into
(4x - 12)(2x + 1)
There are 2 answers
4x - 12 = 0
4x = 12
x = 12/4
x = 3
or
2x + 1 = 0
2x = - 1
x = - 1/2
You have to look at x = -1/2 carefully. The problem is that 4x = 4*(-1/2) = - 2 which is not possible in Euclidean Geometry.
So the only answer is x = 3
Answer:
-22
Step-by-step explanation:
Due to order of operations rules, we must perform the subtraction inside parentheses first, getting:
-4 +(3)(-6)
Multiplication comes next:
-4 - 18
and the total value is thus -22.
