A boutique wants to determine how the amount of time a customer spends browsing in the store affects the amount the customer spends. The equation of the regression line is [tex]\hat{Y} = 2 + 0.9X[/tex].

1. A browsing time of 25 minutes is found to result in an amount spent of 47.5 dollars. What is the predicted amount spent? Where is the observed value in relation to the regression line?

2. A browsing time of 32 minutes is found to result in an amount spent of 27.89 dollars. What is the predicted amount spent? Where is the observed value in relation to the regression line?

3. A browsing time of 4 minutes is found to result in an amount spent of 5.6 dollars. What is the predicted amount spent? Where is the observed value in relation to the regression line?

Note: Please provide your answers in the format "Ex: 1.23 dollars".



Answer :

Sure, let's break this down step-by-step:

### Regression Formula
The equation of the regression line is given by:
[tex]\[ \hat{Y} = 2 + 0.9X \][/tex]
where:
- [tex]\(\hat{Y}\)[/tex] is the predicted amount spent,
- [tex]\(X\)[/tex] is the browsing time in minutes.

We need to determine the predicted amount spent and compare it to the observed value for different browsing times.

### 1. Browsing Time: 25 minutes

Observed Spending: 47.5 dollars

Step 1: Calculate the predicted spending using the regression equation.
[tex]\[ \hat{Y} = 2 + 0.9 \times 25 \][/tex]
[tex]\[ \hat{Y} = 2 + 22.5 \][/tex]
[tex]\[ \hat{Y} = 24.5 \][/tex]

Step 2: Compare the observed spending (47.5 dollars) to the predicted spending (24.5 dollars).
- The observed spending of 47.5 dollars is above the predicted spending of 24.5 dollars.

### 2. Browsing Time: 32 minutes

Observed Spending: 27.89 dollars

Step 1: Calculate the predicted spending using the regression equation.
[tex]\[ \hat{Y} = 2 + 0.9 \times 32 \][/tex]
[tex]\[ \hat{Y} = 2 + 28.8 \][/tex]
[tex]\[ \hat{Y} = 30.8 \][/tex]

Step 2: Compare the observed spending (27.89 dollars) to the predicted spending (30.8 dollars).
- The observed spending of 27.89 dollars is below the predicted spending of 30.8 dollars.

### 3. Browsing Time: 4 minutes

Observed Spending: 5.6 dollars

Step 1: Calculate the predicted spending using the regression equation.
[tex]\[ \hat{Y} = 2 + 0.9 \times 4 \][/tex]
[tex]\[ \hat{Y} = 2 + 3.6 \][/tex]
[tex]\[ \hat{Y} = 5.6 \][/tex]

Step 2: Compare the observed spending (5.6 dollars) to the predicted spending (5.6 dollars).
- The observed spending of 5.6 dollars is on the predicted spending of 5.6 dollars.

### Summary

- Browsing time 25 minutes:
- Predicted amount: 24.5 dollars
- Observed value is above the regression line.

- Browsing time 32 minutes:
- Predicted amount: 30.8 dollars
- Observed value is below the regression line.

- Browsing time 4 minutes:
- Predicted amount: 5.6 dollars
- Observed value is on the regression line.