9514 1404 393
Answer:
nonlinear
Step-by-step explanation:
If the function is linear, evenly-spaced x-values will correspond to evenly-spaced y-values.
Here, the x-values all differ by 1. The y-values differ by 2 and 6, so the function is nonlinear.
Answer:
12
Step-by-step explanation:
of is a another word for multiplying or multiplication
Answer:
Where
and 
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 using the complement rule:

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".
Solution to the problem
Let X the random variable that represent the variable of interest of a population, and for this case we know the distribution for X is given by:
Where
and 
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 using the complement rule:

-21x+31 this is the answer you were looking for
A purchase is one where you purchase it and sales is one you sell :)
Hope that helped!