Suppose we have taken independent, random samples of sizes n1 = 7 and n2 = 7 from two normally distributed populations having means μ1 and μ2, and suppose we obtain x1=240, x2=210, s1=5, and s2 = 6
Use critical values and p-values to test the null hypothesis H0: μ1 − μ2 ≤ 20 versus the alternative hypothesis Ha: μ1 − μ2 > 20 by setting α equal to .10. How much evidence is there that the difference between μ1 and μ2 exceeds 20?
Suppose we have taken independent, random samples of sizes n1 = 7 and n2 = 7...
Suppose that independent samples of sizes n1, n2, . . . , nk are taken from each of k normally distributed populations with means μ1,μ2, . . . , μk and common variances, all equal to σ 2. Let Yi j denote the j th observation from population i, for j = 1, 2, . . . , ni and i = 1, 2, . . . , k, and let n = n1 + n2 + ··· + nk...
Suppose two independent random samples of sizes n1 = 9 and n2 = 7 that have been taken from two normally distributed populations having variances σ21σ12 and σ22σ22 give sample variances of s12 = 100 and s22 = 20. (a) Test H0: σ21σ12 = σ22σ22 versus Ha: σ21σ12 ≠≠ σ22σ22 with αα = .05. What do you conclude? (Round your answers to F to the nearest whole number and F.025 to 2 decimal places.) F = F.025 = (Click to select)RejectDo...
Random samples of sizes n1 = 32 and n2 = 40 are to be drawn from two independent populations. μ1 = 12.3 μ2 = 9.8 σ1 = 2.9 σ2 = 2.4 P(Xbar1 - Xbar 2 < 2) P(S12/ S22 > 2)
Two random samples are selected from two independent populations. A summary of the samples sizes, sample means, and sample standard deviations is given below: n1= 37 n2=44 x-bar1= 58.6 x-bar2= 73.8 s1=5.4 s2=10.6 Find a 97% confidence interval for the difference μ1−μ2μ1−μ2 of the means, assuming equal population variances.
Two random samples are selected from two independent populations. A summary of the samples sizes, sample means, and sample standard deviations is given below: n1=51, n2=46, x¯1=57.8, x¯2=75.3, s1=5.2 s2=11 Find a 94.5% confidence interval for the difference μ1−μ2μ1−μ2 of the means, assuming equal population variances. Confidence Interval =
22) Suppose you want to test the claim that μ1 > μ2. Two samples are randomly selected from each population. The sample statistics are given below. At a level of significance of α = 0.10, find the test statistic and determine whether or not to reject H0. (8.1) n1 = 35 n2 = 42 x1 = 33 x2 = 31 s1 = 2.9 s2 = 2.8 A) z = 3.06; Reject H0 and support the claim that μ1 > μ2...
Independent random samples were selected from two quantitative populations, with sample sizes, means, and standard deviations given below. n1 = n2 = 60 x1 = 125.3 x2 = 123.4 s1 = 5.7 s2 = 6.1 a) Construct a 95% confidence interval for the difference in the population means (μ1 − μ2). (Round your answers to two decimal places.) to b) Find a point estimate for the difference in the population means. c) Calculate the margin of error. (Round your answer...
1) Consider two independent random samples of sizes n1 = 14 and n2 = 14, taken from two normally distributed populations. The sample standard deviations are calculated to be s1= 1.98 and s2 = 5.71, and the sample means are x¯1=-10.2and x¯2=-2.34, respectively. Using this information, test the null hypothesis H0:μ1=μ2against the one-sided alternative HA:μ1<μ2, using Welch's 2-sample t Procedure for independent samples. a) Calculate the value for the t test statistic. Round your response to at least 2 decimal...
Independent random samples selected from two normal populations produced the sample means and standard deviations shown below: Sample 1 Sample 2 x̅1 = 5.4 x̅2 = 8.2 s1 = 5.6 s2 = 8.2 n1 = 20 n2 = 18 Conduct the test H0 : μ1 - μ2 = 0 against H1 : μ1 - μ2 ≠ 0 ,then the test statistic is __________.
Two samples are taken with the following sample means, sizes, and standard deviations ¯ x1 x¯1 = 31 ¯ x2 x¯2 = 28 n1 n1 = 70 n2 n2 = 46 s1 s1 = 4 s2 s2 = 2 We want to estimate the difference in population means using a 89% confidence level. What distribution does this require? t, df = 108 z NOTE: The more accurate df formula, used above, is: df= ( s 2 1 n1 + s...