Answer:
A, She added before multiplying.
Step-by-step explanation:
First, start off by using GEMDAS.
Grouping
Exponents
Multiply
Divide
Add
Subtract
You work from left to right - so you obviously divide first, which Amanda did successfully. Then, you multiply, which is exactly where Amanda went wrong. She was supposed to multiply before adding the 3 with 4.
Not sure if this made sense,
Answer:
7
Step-by-step explanation:
σ = 4 ; μ =?
8.52 to the left of X
.
P(X < 8.52) = 64.8%
P(X < 8.52) = 0.648
Using the Z relation :
(x - μ) / σ
P(Z < (8.52 - μ) / 4)) = 0.648
The Z value of 0.648 of the lower tail is equal to 0.38 (Z probability calculator)
Z = 8.52 - μ / 4
0.38 = 8.52 - μ / 4
0.38 * 4 = 8.52 - μ
1.52 = 8.52 - μ
μ = 8.52 - 1.52
μ = 7
You will need to add all the dimensions together, also know as perimeter