Question

Consider this scatter plot.

Answer 1

Answer:

Part a) Is a positive correlation

Part b) $\ 69.5$

Part c) see the explanation

Step-by-step explanation:

Let

x ----> the number of items sold

y ----> the money spent on advertising

Part a) How would you characterize the relationship between money spent on advertising and items sold?

we know that

Positive correlation is a relationship between two variables in which both variables move in the same direction

so

As the value of x increases, the value of y increases

therefore

Is a positive correlation

Part b) Sally uses the function y = 1.6x + 21.5 to model the situation. What score does the model predict should be spent in advertising to sell 30 items?

we have

$y=1.6x+21.5$

For x=30 items

substitute the value of x in the linear equation and solve for y

$y=1.6(30)+21.5=\ 69.5$

Part c) What does the number 21.5 in Part (b) mean in the context of the situation?

we have

$y=1.6x+21.5$

This is a linear equation in slope intercept form

where

The slope is

$m=\ 1.6\ per\ item\ sold$

The y-intercept or initial value is

$b=\ 21.5$

therefore

In the context of the situation the number 21.5 means the initial amount spent at the begin (when the number of items sold was zero)