To find the residual of the data point (6, 7.82), you first need to calculate the predicted height of the plant on day 6 using the line of best fit equation \( y = 0.23x + 9.9 \).
- Substitute \( x = 6 \) into the equation:
\[ y = 0.23(6) + 9.9 \]
- Calculate \( 0.23(6) \):
\[ 0.23 \times 6 = 1.38 \]
- Add this result to 9.9:
\[ y = 1.38 + 9.9 = 11.28 \]
The predicted height of the plant on day 6 is 11.28.
- Now, calculate the residual by finding the difference between the actual height and the predicted height:
\[ \text{Residual} = \text{Actual} - \text{Predicted} \] \[ \text{Residual} = 7.82 - 11.28 \] \[ \text{Residual} = -3.46 \]
The residual of the data point (6, 7.82) is \(-3.46\).
Thus, the answer is:
-3.46.