What is the equation of the line that passes through the point
(1,3) and has a slope of −3?

y = -3x + 6

Step-by-step explanation:

The equation for slope-intercept form is y = mx + b, where m=slope and b=y-intercept.

First, we want to plug in our slope.

y = -3x + b

Next, we take our coordinate pair (1,3) and plug it in to solve for b. Remember that it's in the form (x, y).

y = -3x + b

3 = -3(1) + b

3 = -3 + b

3+3 = b

6 = b

Now put b back in to get our full equation:

y = -3x + 6

And we can find this probability using the z table and we got:

Step-by-step explanation:

Let X the random variable that represent the thickness 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 z table and we got: