Question 1 (10 Marks)

As part of an investigation into the management of household waste, a random sample of 404 households was taken and, for each, data was collected on:

WASTE: The amount of waste produced per week (kg)

SIZE: The size of the house (m²)

CHILDREN: The number of children normally living in the house

ADULTS: The number of adults normally living in the house

These variables were used to build a regression equation:

WASTE = 7.194 + 0.0002SIZE + 1.103CHILDREN + 1.042ADULTS

R²= 0.352

(a)What is the predicted weekly waste for a house covering 200 m²comprising 2 adults and 3 children?

[2 Marks]

.......................................................................................12.627 KG...............

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(b)What does the R²figure indicate?What does it tell you about any predictions

[2 Marks]

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(c)What does the coefficient of 0.0002 for SIZE tell you about the effect of an extra square metre of floor space on household waste?

[2 Marks]

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(d)What is the predicted weekly waste for a house covering 5000 m²comprising 1 adult and 0 children?How good do you think this prediction is likely to be bearing in mind that the largest household in the sample of 404 is 236 m²in size? (your answer should not exceed 100 words)

[4 Marks]

9.236 KG......................................................................................................................

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