We have determined p = 0.64, z = 1.645, and n = 1,030. Use these values to construct a 90% confidence interval for the population proportion, rounding the results to three decimal places. p + (z critical value) P(1 - p) 0.64(1 - 0.64) = 0.64 + 1.645, 1,030 ]× ) .6646 -.6153

If n1 = 120, x1 = 45, n2 80, x2 = 35. Calculate the 98% confidence interval for p1-p2. O (-0.172,0.144) O (-0.197,0.111) O (-0.227,0.101) O (-0.379, -0.021)

A 99% confidence interval for a population mean based on a sample of size 64 is computed to be (16.3, 18.7). How large a sample is needed so that a 99% confidence interval will specify the mean to within ±1 .0?

A 95% confidence interval for μA -μg is given by (-2.3, 4.5). What can we infer from this confidence interval? (A) This confidence interval implies that the mean for sample A is less than the mean for sample B. (B) This confidence interval implies that the mean for sample A is equal to the mean for sample B. (C) With 95% confidence, there is convincing statistical evidence that the mean for population A is less than the mean for population B. (D) With 95% confidence, there is convincing statistical evidence that the mean for population A is greater than the mean for population B. (E) There is not convincing statistical evidence that the mean for population A is different from the mean for population B at the 5% significance level.