The following data relate the mother's age and the birthweight (in grams) of her child.
Birthweight
|
Maternal Age
|
Less Than 2,500 Grams
|
More Than 2,500 Grams
|
|
20 years or less
|
10
|
40
|
|
Greater than 20
|
15
|
135
|
Test the hypothesis that the baby's birthweight is independent of the mother's age.