Question

Medal for best answer!!!!!!!!!!


An equation was used to predict possible sales of phones for 6 months. The actual sales of phones are also listed.

Actual sales 55 150 325 510 780 990
Predicted sales 40 150 300 500 800 1,000
The sum of the residuals is

Answer 1

Can someone plz help me???

Answer 2

What is a residual?

Answer 3

Observed value-predicted value or e-y=y

Answer 4

Stat Trek says....

Residual
In regression analysis, the difference between the observed value of the dependent variable (y) and the predicted value (ŷ) is called the residual (e). Each data point has one residual.

Residual = Observed value - Predicted value
e = y - ŷ

You are correct and I learned something. Looks pretty straight forward once you know the definition....

Actual sales 55 150 325 510 780 990 Observed Values
Predicted sales 40 150 300 500 800 1,000 Predicted Values
15 0 25 10 -20 -10 Add these numbers up

The sum of the residuals is _____ ?

Answer 5

20

Answer 6

Okay I got it can u help me with another one?

Answer 7

The table below shows the age of some participants in a quiz competition and the number of questions they could answer correctly:

Age (years) (x) 15 21 17 22 16 19 18
Number of questions they could answer (y) 17 17 17 17 17 17 17
What is the correlation coefficient for the data, and what does it represent? (5 points)


0; it represents no correlation between x and y

1; it represents a linear positive correlation between x and y

1; it represents a linear negative correlation between x and y

−1; it represents a linear negative correlation between x and y

Answer 8

I think it is the C

Answer 9

Why?

Answer 10

Actualy I am not sure

Answer 11

Graph the data with the x axis being the age and the y axis being the number of questions they got could answer correctly.

Answer 12

It should be like a straight line because the number of questions are the same for everyone

Answer 13

Exactly straight line

Answer 14

That is correct.

What is the slope of that line?

Answer that and you will have your correlation.

Answer 15

So no correlation I what a straight line would be right?

Answer 16

Am I correct?

Answer 17

Can u tell me If i am correct or not so that we can go on?