The following results come from two independent random samples taken of two populations. Sample 1 n₁ = 60 x₁ = 13.6 Sample 2 n₂ = 25 x₂ = 11.6 %₁ = 2.4 (a) What is the point estimate of the difference between the two population means? (Use x₁ - x₂.) %₂ = 3 to (b) Provide a 90% confidence interval for the difference between the two population means. (Use X₁ X₂. Round your answers to two decimal places.) (c) Provide a 95% confidence interval for the difference between the two population means. (Use x₁ - x₂. Round your answers to two decimal places.) to

#21)

Suppose we have two normal populations denoted A and B, and we want to compare their population variances by estimating the ratio: variance of population B divided by variance of population A.  We have an independent random sample of size 15 from population A and an independent random sample of size 9 from population B.  The sample variance for population B turns out to be 30 percent larger than that for population A.  What is the 99 percent confidence interval for the ratio:  population variance of population B divided by population variance of population A?  Use stattrek.org for finding the needed critical values.

Can you solve this problem about the confidence interval?

Given two independent random samples with the following results: n1=12x‾1=73s1=27n1=12x‾1=73s1=27   n2=12x‾2=102s2=22n2=12x‾2=102s2=22 Use this data to find the 95%95% confidence interval for the true difference between the population means. Assume that the population variances are equal and that the two populations are normally distributed.   Step 1 of 3 :   Find the point estimate that should be used in constructing the confidence interval.

Zα/2 for the 96% confidence interval

X. is found to be 19.1, and the A simple random sample of sizen is drawn from a population that is normally distributed. The sample mean, sample standard deviation, s, is found to be 4.9. (a) Construct a 96% confidence interval about u if the sample size, n, is 39. (b) Construct a 96% confidence interval about u if the sample size, n, is 68. How does increasing the sample size affect the margin of error, E? (c) Construct a 98% confidence interval about u if the sample size, n, is 39. How does increasing the level of confidence affect the size of the margin of error, E? (d) If the sample size is 14, what conditions must be satisfied to compute the confidence interval? (a) Construct a 96% confidence interval about u if the sample size, n, is 39. Lower bound: Upper bound: (Round to two decimal places as needed.) (b) Construct a 96% confidence interval about u if the sample size, n, is 68. Lower bound: ; Upper bound: (Round to two decimal places as needed.) How does increasing the sample…

7. What is the 95% confidence interval for the difference in the population means, µ1 - µ2, given the data from the two independent samples: n1 =56, x1= 58.2, s1= 4.3, n2=45, x2=60.2, s2=5.5 B. [-3.28 , -0.72] C. [-3.60, -0.40] D. [-3.65 , -0.35] A. [-3.96 , -0.04] 8. What is the 98% confidence interval for the difference in the population means, µ1 - µ2, given: n1= 22, x1= 41.4, s1= 5.9, n2= 19, x2= 43.2, s2= 6.5  D. [-3.48 , -0.12] B. [-3.07 , -0.53] A. [-3.12, -0.48] C. [-3.18, -0.42]