Answer is 47
Reason : degree of freedom is n1 + n2 - 2 , here 22 + 27 - 2 = 49 - 2 = 47
A researcher collects two independent random samples of sizes n = 22 and n2 = 27,...
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 =
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...
Question We are doing a two-mean pooled t-test. We have two samples with sizes n = 13 and n2 = 24. The population standard deviations are unknown but assumed to be equal, so we find the sample standard deviations and use them to calculate a pooled standard deviation, Sp- • For sample 1: S1 = 9.4 and 1 = 47 • For sample 2: s2 = 8.7 and iz = 44 What are the test statistic (I) and the degrees...
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...
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...
Independent random samples were selected from two quantitative populations, with sample sizes, means, and standard deviations given below. n1= 55, n2= 65, xbar1= 35.5, xbar2= 31.4, s1= 5.7, s2= 3.3 1.) Construct a 95% confidence interval for the difference in the population means (mu1- mu2). (Round your answers to two decimal places) 2.) Find a point estimate for the fifference in the population means. 3.) Calculate a margin of error. (Round your answer to two decimal places)
help Two samples are taken with the following sample means, sizes, and standard deviations īj = 29 12 = 36 71 = 72 n2 = 53 81 = 482 = 3 We want to estimate the difference in population means using a 86% confidence level. What distribution does this require? Oz Ot, df = 123 NOTE: The more accurate df formula, used above, is: 2 + 1 72 df 2 2 + - ni 12 1 12 What is a?...
Two samples are taken with the following sample means, sizes, and standard deviations 21 = 24 m2 = 31 ni = 60 n2 = 65 $1 = 5 82 = 3 Estimate the difference in population means using a 89% confidence level. Use a calculator, and do NOT pool the sample variances. Round answers to the nearest hundredth. <Hi - 42
Two samples are taken with the following sample means, sizes, and standard deviations ¯x1 = 25 ¯x2 = 23 n1 = 54 n2 = 73 s1 = 5 s2 = 3 Estimate the difference in population means using a 88% confidence level. Use a calculator, and do NOT pool the sample variances. Round answers to the nearest hundredth.