Answer:
The mean of the total repair time is 150 minutes.
The variance of the total repair time is 725 minutes^2.
Step-by-step explanation:
To solve this problem, we have to use the properties of the mean and the variance. Our random variable is the sum of 3 normal variables.
In the case, for the mean, we have that the mean of the sum of 3 normal variables is equal to the sum of the mean of the 3 variables:

For the variance, we apply the property for the sum of independent variables (the correlation between the variables is 0):

Answer:
132
Step-by-step explanation:
calculator says so.
Answer:
x=1
Step-by-step explanation:
Add 3 to both sides
6x=3+3
Simplify 3 + 3 to 6
6x=6
Divide both sides by 6
x=1
Answer:
The answer is 24/<u>2</u>=<u>36</u>/3=<u>66</u>/5.5=108/<u>9</u>=<u>180</u>/15.
Step-by-step explanation:
Given:
24/2=_/3=_/5.5=108/_=_/15.
Now, we need to solve this by putting
in the place of _ and then continue:

<em>By</em><u><em> cross multiplication we get:</em></u>

By dividing with 2 we get:

Now, <u><em>we will continue like this process:</em></u>



And, then again:



And, last:



Therefore, the answer is 24/<u>2</u>=<u>36</u>/3=<u>66</u>/5.5=108/<u>9</u>=<u>180</u>/15.