The regression equation is , and it will take 31 weeks to have $50.00
<u>(a) The linear regression equation</u>
To do this, we make use of a graphing calculator;
From the graphing calculator, we have the following calculation summary:
- The sum of X = 45
- The sum of Y = 83
- Mean X = 4.5
- Mean Y = 8.3
- Sum of squares (SSX) = 82.5
- Sum of products (SP) = 128.5
The regression equation is then represented as:
Where:
and
So, we have:
Approximate
Approximate
This means that, the regression equation is
<u>(b) Predict the time to have $50.00</u>
This means that:
So, we have:
Subtract 1.29 from both sides
Divide both sides by 1.56
Rewrite as:
Approximate
Hence, it will take 31 weeks to have $50.00
Read more about linear regression models at: