Divide through everything by <em>b</em> :

Since <em>a/b</em> < <em>c/d</em>, it follows that

Multiply through everything on the right side by <em>b/d</em> to get

and so (<em>a</em> + <em>c</em>)/(<em>b</em> + <em>d</em>) < <em>c/d</em>.
For the other side, you can do something similar and divide through everything by <em>d</em> :

and <em>a/b</em> < <em>c/d</em> tells us that

Then

and so (<em>a</em> + <em>c</em>)/(<em>b</em> + <em>d</em>) > <em>a/b</em>.
Then together we get the desired inequality.
Answer:

And replacing we got:

And we can calculate this probabilit using the normal standard distribution or excel and we got:

Step-by-step explanation:
If we define the random variable of interest "the amount spent by a family of four of food per month" and we know the following parameter:

And we want to find the following probability:

And we can use the z score formula given by:

And replacing we got:

And we can calculate this probabilit using the normal standard distribution or excel and we got:

Answer: Line 2
Step-by-step explanation:
Look at the dots on the coordinate grid. The line of fit is a line around those dots, so in this case, the majority of the dots around line 2.
Answer:
cool beans
Step-by-step explanation:
There are no coordinates listed, Sorry.