The table below gives the list price and the number of bids received for five randomly selected items sold through online auctions. Using this data, consider the equation of the regression line [tex]\(\hat{y} = b_0 + b_1 x\)[/tex], for predicting the number of bids an item will receive based on the list price.

[tex]\[
\begin{tabular}{|c|c|c|c|c|c|}
\hline
Price in Dollars & 22 & 25 & 32 & 33 & 38 \\
\hline
Number of Bids & 3 & 5 & 6 & 9 & 10 \\
\hline
\end{tabular}
\][/tex]

Step 1 of 6: Find the estimated slope. Round your answer to three decimal places.



Answer :

To find the estimated slope [tex]\( b_1 \)[/tex] of the regression line [tex]\( \hat{y} = b_0 + b_1 x \)[/tex], we need to analyze the relationship between the prices and the number of bids. Here, we are using the method of least squares linear regression.

Given data:
- List Price (x) in Dollars: [22, 25, 32, 33, 38]
- Number of Bids (y): [3, 5, 6, 9, 10]

The formula for the estimated slope [tex]\( b_1 \)[/tex] in a simple linear regression model is:
[tex]\[ b_1 = \frac{n\sum (xy) - \sum x \sum y}{n\sum (x^2) - (\sum x)^2} \][/tex]

Where:
- [tex]\( n \)[/tex] is the number of data points.
- [tex]\( \sum (xy) \)[/tex] is the sum of the product of paired scores.
- [tex]\( \sum x \)[/tex] is the sum of the x-values.
- [tex]\( \sum y \)[/tex] is the sum of the y-values.
- [tex]\( \sum (x^2) \)[/tex] is the sum of the squares of the x-values.

However, through calculations, the estimated slope is found to be:

[tex]\[ b_1 \approx 0.422 \][/tex]

This value of 0.422 indicates that for each additional dollar increase in the price, the number of bids is expected to increase by approximately 0.422, all else being equal.