Fit a straight line [tex]\( y = a + bx \)[/tex] to the following data:

[tex]\[
\begin{array}{cccccc}
X: & 2 & 5 & 6 & 8 & 9 \\
Y: & 8 & 14 & 19 & 20 & 31 \\
\end{array}
\][/tex]

Predict [tex]\( Y \)[/tex] when [tex]\( X = 9.6 \)[/tex].



Answer :

To fit a straight line [tex]\(y = a + bx\)[/tex] to the given data and predict [tex]\(Y\)[/tex] when [tex]\(X = 9.6\)[/tex], follow these steps:

1. Identify the Data Points:
The provided data points are:
[tex]\[ X: 2, 5, 6, 8, 9 \][/tex]
[tex]\[ Y: 8, 14, 19, 20, 31 \][/tex]

2. Determine the Coefficients [tex]\(a\)[/tex] and [tex]\(b\)[/tex]:
We need to find the coefficients [tex]\(a\)[/tex] (the y-intercept) and [tex]\(b\)[/tex] (the slope) of the line [tex]\(y = a + bx\)[/tex] that best fits the data.

After calculations, the coefficients are found to be:
[tex]\[ a \approx 1.000 \][/tex]
[tex]\[ b \approx 2.900 \][/tex]

3. Form the Equation of the Line:
Using the coefficients [tex]\(a\)[/tex] and [tex]\(b\)[/tex], the equation of the best-fit line is:
[tex]\[ y = 1.000 + 2.900x \][/tex]

4. Predict [tex]\(Y\)[/tex] for [tex]\(X = 9.6\)[/tex]:
To predict the value of [tex]\(Y\)[/tex] when [tex]\(X = 9.6\)[/tex], substitute [tex]\(X = 9.6\)[/tex] into the equation of the line:
[tex]\[ y = 1.000 + 2.900 \times 9.6 \][/tex]

Performing the calculation:
[tex]\[ y \approx 1.000 + 27.84 = 28.84 \][/tex]

5. Result:
So, the predicted value of [tex]\(Y\)[/tex] when [tex]\(X = 9.6\)[/tex] is:
[tex]\[ Y \approx 28.84 \][/tex]

Therefore, the values of the coefficients are [tex]\(a \approx 1.000\)[/tex] and [tex]\(b \approx 2.900\)[/tex], and the prediction for [tex]\(Y\)[/tex] when [tex]\(X = 9.6\)[/tex] is approximately 28.84.