Chapter 26, Problem 19E

a)

To determine

To show how to calculate residuals.

Explanation of Solution

Given:

  

  

Formula:

  $\mathrm{Re}sidual=\frac{O-E}{\sqrt{E}}$

Calculation:

First, we will calculate the residual for smallest count.

  $\mathrm{Re}sidual=\frac{190-159.3413}{\sqrt{159.3413}}=2.43$

In that way all the residuals can be calculated.

		Epidural?
		Yes	No
Breastfeeding at 6 months	Yes	-1.99	1.42
No	2.43	-1.73

b)

To determine

To state a conclusion from residuals.

Answer to Problem 19E

The babies whose mothers were given the epidural, were less likely to be breastfeeding after 6 months.

Explanation of Solution

Given:

  

		Epidural?
		Yes	No
Breastfeeding at 6 months	Yes	-1.99	1.42
No	2.43	-1.73

From the residuals and observed count, it can be concluded that the babies whose mothers were given the epidural, were less likely to be breastfeeding after 6 months.