Using the identity (a+b)(a+b) = a^2 + 2ab + b^2 we get the answer 4Z^2 + 20Z + 25
Multiply out the bracket so
-27 + 36w - 8w
Then collect the terms so
-27 + 28w
Answer = - 27 + 28w
Given that variance of a data set is:
Variance=σ²
the standard deviation is the square root of the variance:
thus
standard deviation= √(variance)
variance,σ²=104.04
thus
std deviation=√σ²=√104.04
thus
σ=10.2
*+:｡.｡ I put the answer in the comments, for people who’ve run out of answers! ｡.｡:+*
