One provision of the Affordable Care Act, commonly known as Obamacare, requires insurance plans pay for breast feeding support for mothers, such as consultations and breast pumps. According to the CDC, 48% of mothers were breast feeding their six month old babies in 2012. Suppose Humana Health Insurance would like to estimate the proportion of mothers who breast fed their children at six months in 2014. A random sample of 210 mothers with six month old babies was selected of which 119 were breast feeding.

a. Construct a 95% confidence interval to estimate the actual proportion of mothers with six month old babies that were breast feeding in 2014.

b. What is the margin of error for this sample?

c. Is there evidence that this proportion has changed since 2012 based on this sample?

d. Verify your results with PHStat.