The correlation coefficient is a number that indicates the direction
and closeness of points of a line of best of fit.
So it tells us two things.
It tells us the direction of the line of best fit
and it tells us the closeness of the points.
Usually, anything between -0.9 and -0.6 has a moderate negative correlation. If you look at this on a graph, you will notice that the points definitely resemble a line so we say it's moderate.
It will be a negative correlation because the slope is negative.
The probability is found from a suitable table or probability calculator.
p(z < 1.3) ≈ 0.9031995154
I think 12 might be the second one, I'm not sure though!
(0,-1)(1,0)(2,3)(3,8)(4,15)
The two black circles represents "The selling prices that produces no profit." If the selling is 10, the profit is 0. If the selling price is 60, the profit is 0.
The selling price that provides the maximum profit is represented by the red dot. It is between the selling price of 30 and 40. Its maximum profit is equal to 12,000.
