Question

Please help and NO LINKS I WILL REPORT YOU IF ITS A LINK

Emi computes the mean and variance for the population data set 87, 46, 90, 78, and 89. She finds the mean is 78. Her steps for finding the variance are shown below.

What is the first error she made in computing the variance?
A.) Emi failed to find the difference of 89 - 78 correctly.
B.) Emi divided by N - 1 instead of N.
C.) Emi evaluated (46 - 78)2 as -(32)2.
D.) Emi forgot to take the square root of -135.6.

Answer 1

Answer: Choice C) Emi evaluated (46-78)^2 as -(32)^2

Step-by-step explanation:

The "46-78" is inside the parenthesis, so the result must also stay in the parenthesis. This means (46-78)^2 would become (-32)^2. The negative must be inside the parenthesis as well. Squaring the "-32" leads to a positive result, so every item being added is positive after the squaring operations are applied.