Answer:
The z-distribution should be used for this problem.
Step-by-step explanation:
The population distribution is assumed to be normal. Which distribution to use?
If we have the standard deviation for the sample, we use the t-distribution.
If we use the standard deviation for the population, we use the z-distribution.
There is a known standard deviation of 2.2 minutes.
This means that 2.2 is the population standard deviation, and thus, the z-distribution should be used for this problem.
Answer:

Step-by-step explanation:
We want to calculate the right-endpoint approximation (the right Riemann sum) for the function:

On the interval [-1, 1] using five equal rectangles.
Find the width of each rectangle:

List the <em>x-</em>coordinates starting with -1 and ending with 1 with increments of 2/5:
-1, -3/5, -1/5, 1/5, 3/5, 1.
Since we are find the right-hand approximation, we use the five coordinates on the right.
Evaluate the function for each value. This is shown in the table below.
Each area of each rectangle is its area (the <em>y-</em>value) times its width, which is a constant 2/5. Hence, the approximation for the area under the curve of the function <em>f(x)</em> over the interval [-1, 1] using five equal rectangles is:

Let's solve your inequality step-by-step.
5x<30
Step 1: Divide both sides by 5.
5x
5
<
30
5
x<6
Answer:
you have to use cross-multiplication in order to find out the answer to this question.
Step-by-step explanation:
9/12 times 2/3