The answer to your question is in this order :
-10, 0, 11, 20
Answer:

Step-by-step explanation:
Previous concepts
Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".
The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".
Let X the random variable that represent the Shear strength of a population, and for this case we know the distribution for X is given by:
Where
and 
And let
represent the sample mean, the distribution for the sample mean is given by:

On this case 
We are interested on this probability

And the best way to solve this problem is using the normal standard distribution and the z score given by:

If we apply this formula to our probability we got this:


And we can find this probability on this way:

And in order to find these probabilities we can find tables for the normal standard distribution, excel or a calculator.

Answer:
12 blocks west
Step-by-step explanation:
Okay so he walked 12 blocks west to Zac's house and then walked another 12 blocks back this means that he had to walk 12 blocks west to get to Zac's house
P.S. Sorry if it is wrong
Answer:
Step-by-step explanation: