Answer:
a) The confidence interval is
.
Step-by-step explanation:
We have to calculate a confidence interval (CI) of a difference of proportions.
For the existing procedure, the proportion is:

For the new procedure, the proportion is:

To calculate the CI, we need to estimate the standard deviation

For a 90% CI, the z-value is 1.64.
Then, the CI is:

Answer:
Jasmine ran last week 37.2 miles
Step-by-step explanation:
Let
x ----> number of miles Rob ran last week
y ----> number of miles Jasmine ran last week
we know that
x=y-27.2 ----> equation A
x=10 ----> equation B
Substitute equation B in equation A and solve for y
10=y-27.2
y=10+27.2
y=37.2 miles
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.
You are right about the domain.
Answer:
10
Step-by-step explanation:
Yesterday, Priya successfully made 6 free throws.
Today, she made 75% as many as yesterday.
We are asked to calculate the number of successful free throws that Priya made today.
So, the number will be
.
Since it is the number of successful free throws, so it will be 10 throws. ( Answer )