Because the confidence interval contains the critical value, there appears to be a significant difference between the two proportions. because the confidence interval consists ▼ ▼ the critical value, the significance level, 0, the pooled sample proportion, it appears that the first proportion is ▼ not significantly different from less than greater than the second proportion. there is ▼ insufficient sufficient evidence to support the claim that the rate of polio is less for children given the vaccine than it is for children given a placebo.