For women who are pregnant with twins, complete bed rest in late pregnancy is commonly prescribed in order to reduce the risk of premature delivery. To test the value of this practice, 212 women with twin pregnancies were randomly allocated to a bed-rest group or a control group. The accompanying table shows the incidence of preterm delivery (less than 37 weeks of gestation).

Construct a 95% confidence interval for (Pr{ preterm | bed rest} - Pr{preterm | control}). Does the confidence interval suggest that bed rest is beneficial?

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Bed rest Controls No. of preterm deliveries No. of women 32 105 20 107