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The given figure shows a line fit using least squares method between profit in chocolate business and mean temperature (T) data for a city. The correl
Question

The given figure shows a line fit using least squares method between profit in chocolate business and mean temperature (T) data for a city. The correlation coefficient obtained from this data is r. Which one of the following statements is INCORRECT?

A.

The sum of the squared differences between the observed and estimated values of profit is minimum.

B.

About 69% of the variation in profit is explained by the variation intemperature.

C.

At 30°C, estimated profit is 34 million Rs.

D.

Data point (32, 80) is anomalous and therefore must be discarded.

Correct option is D

Given Information from the Graph:

  • Regression equation:
    Profit = 4T - 86
  • Correlation coefficient:
    r = 0.83

Option A:

Statement: "The sum of the squared differences between the observed and estimated values of profit is minimum."

This is CORRECT.

Explanation: This is the fundamental principle of the least squares method. It always minimizes the sum of the squared differences between the actual observed values and the predicted values from the regression line.

Option B:

Statement: "About 69% of the variation in profit is explained by the variation in temperature."

This is CORRECT.

Explanation: The coefficient of determination is r².
So, r = 0.83 → r² = 0.83 × 0.83 = 0.6889 ≈ 69%.
This means about 69% of the variation in profit is explained by temperature.

Option C:

Statement: "At 30°C, estimated profit is 34 million Rs."

This is CORRECT.

Check using the regression equation:
Profit = 4 × 30 - 86 = 120 - 86 = 34 million Rs.

Option D:

Statement: "Data point (32, 80) is anomalous and therefore must be discarded."

This is INCORRECT.

Explanation:
Although the point (32, 80) appears to deviate from the line, it should not be immediately discarded. Outliers need proper statistical justification before removal.
Also, the correlation coefficient (r = 0.83) indicates a strong positive relationship, so the data is still reliable overall.

Final Answer: (D) is the incorrect statement.

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