1st use the Step! Please, Excuse, My, Dear, Aunt, Sally! Ehich also means (PEMDAS) Parenthesis (), Exponents ", Multiple ×, Division÷, Addition+, and Subtraction-. Than your going to solve! (3n+5)×9=n×7
27n+45=7n
27n-7n=-45
20n=-45
n=-45/20= -9/4
Answer:
a) 121,000
b)8.35 x 10^-6
Step-by-step explanation:
Answer:
.
Step-by-step explanation:
Answer:
1932 credit hours
Step-by-step explanation:
Create a proportion
credits credits
---------- = ----------
students students
14 ?
---- = -----
1 138
14 times 138
1932 credit hours
Answer:
3.4
Step-by-step explanation:
Standard deviation of a population is defined as:
σ² = ∑(xᵢ − μ)² / n
The standard deviation of a sample is defined as:
s² = ∑(xᵢ − x)² / (n - 1)
It's not clear which one we have, so let's calculate both.
First, we must find the mean.
μ = (5+12+15+10+12+6+8+8) / 8
μ = 9.5
Now we find the squares of the differences:
(5-9.5)² + (12-9.5)² + (15-9.5)² + (10-9.5)² + (12-9.5)² + (6-9.5)² + (8-9.5)² + (8-9.5)²
= 80
Divide by n:
σ² = 80 / 8
σ² = 10
And take the square root:
σ = √10
σ ≈ 3.2
That's not one of the answers, so let's try the standard deviation of a sample instead of a population.
Instead of dividing by n, we'll divide by n-1:
s² = 80 / 7
And take the square root:
s = √(80/7)
s ≈ 3.4
So that must be it.
