Question

1. The following table displays the weight of newborn babies together with their mother’s weight immediately after giving birth.

Baby Weight (kilograms)	Mother’s Weight (kilograms)
3.8	61.5
3.4	58.6
3.2	56.4
3.5	57.1
3.5	57.8
3.6	59.0
3.7	60.3

1. [3 marks] Is there a significant correlation between the two variables?
2. [5 marks] Determine the linear regression equation for the data.
3. [1 mark] Determine the weight of a mother who gave birth to a 3.0 kilogram baby.
4. [1 mark] If a new mother weights 58.0 kilograms after giving birth, how much did her baby weigh?

Answer 1

a. Is there a significant correlation between the two variables?

Yes. There is a significant positive correlation between two variables.

Because the trend is showing the straight line positive relationship.

Correlation coefficient = 0.89

Formula in excel: "=CORREL(Array 1, Array 2)

b. Determine the linear regression equation for the data.

y = 8.0915x + 30.12

Determine the weight of a mother who gave birth to a 3.0 kilogram baby.

x = 3

y = 8.0915x + 30.12

y = 8.0915*(3.0)+30.12

y = 54.39

The weight of the mother is 54.39

If a new mother weights 58.0 kilograms after giving birth, how much did her baby weigh?

3.46

y = 0.099x - 2.2782

y =0.099*58 - 2.2782

y = 3.46