Step-by-step explanation:
a. First, find the z-score.
z = (x − μ) / σ
z = (80 − 74.0) / 12.5
z = 0.48
Use a calculator or table to find the probability.
P(z < 0.48) = 0.6844
b. Find the standard deviation of the sample.
σₓ = σ / √n
σₓ = 12.5 / √4
σₓ = 6.25
Find the z-score.
z = (x − μ) / σ
z = (80 − 74.0) / 6.25
z = 0.96
Use a calculator or table to find the probability.
P(z < 0.96) = 0.8315
c. When the distribution of the population is normal, then the distribution of the sample mean is also normal.
Step-by-step explanation:
Let's translate the verbal language to algebraic language.
She rides to and from school 5 days per week, 6.25 miles each route => 5*2*6.25 miles = 62.5 miles.
She rides additioanly around the park 2.5 miles for each trip t => 2.5*t = 2.5t
Total miles of her rides per week: 62.5 miles + 2.5t
She wants to ride minimum 85 miles => 62.5 + 2.5t ≥ 85
Then, the situation is represented by this inequality:
2.5t + 62.5 ≥ 85
You can develop it and get to several equivalent inequalities, for example:
2.5t ≥ 85 - 62.5
2.5t ≥ 22.5
t ≥ 9
Any of the four forms are equivalent and a valid answer.
Answer:
The possible combinations of two letters is 12
Step-by-step explanation:
Here, we want to count the possible combinations of two letters
Now, for the first letter any point in time, we have 4 letters to pick from,
For the second letter we have 3 letters to pick from
So therefore, we have the possible combinations as;
4 * 3 = 12
Answer:
A ITS A
because 9*9*9 and it divides by 2
Answer:
4 hrs
Step-by-step explanation:
Total gallons that are in the plane = 48
Used for takeoff and landing = 7.
Remaining that is left to be used while in air = 48-7
= 41.
maximum number of hours the plane can remain in the air= Maximum of ( 
)
So maximum of 4 hours.
