Independent random samples of n = 100 observations each are drawn from normal populations. The parameters of these populations are:
• Population 1: μ1 = 300 and σ1 = 60;
• Population 2: μ2 = 290 and σ2 = 80.
(1) What is the probability that the mean of Population 1 is
between 294 and 306?
(2) How many samples should be included if we want the probability
in Part (1) to be at least 95%? (3) What is the
probability that the mean of Population 1 is greater than the mean
of Population 2?
Independent random samples of n = 100 observations each are drawn from normal populations. The parameters...
Independent random samples of n = 16 observations each are drawn from normal populations. The parameters of these populations are: Population 1: u = 279 and o = 25 Population 2: j = 268 and o = 29 Find the probability that the mean of sample 1 is greater than the mean of sample 2 by more than 16. Probability =
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)
The following information is obtained from two independent samples selected from two populations. n1=270 x¯1=5.98 σ1=1.11 n2=210 x¯2=5.40 σ2=2.47 Test at the 2% significance level if μ1 is greater than μ2 (one-tailed test). μ1 is Choose the answer from the menu in accordance to the question statement μ2 .
you select two independent random samples from populations with means u1 and u2. suppose the sample mean for population 1 is 25 and σ1=3 and the sample mean for population is 20 and σ2=4. the 95% confidence interval for u1-u2 is (4.02,5.98). what common sample size, n, was used to obtain this interval?
Independent random samples of 36 and 41 observations are drawn from two quantitative populations, 1 and 2, respectively. The sample data summary is shown here. Sample 1 36 Sample 2 Sample Size Sample Mean 1.32 0.05700.0520 Do the data present sufficlent evidence to indicate that the mean for population I is smaller than the mean for population 27 Use one of the two methods of testing presented in this section. (Round your answer to two decimal places.) z 2877
Suppose you wish to compare the means of six populations based on independent random samples, each of which contains 5 observations. The values of Total SS and SSE for the experiment are Total SS = 21.1 and SSE = 16.5. The sample means corresponding to populations 1 and 2 are x1 = 3.06 and x2 = 2.21. 1. Find a 95% confidence interval for μ1. (Round your answers to three decimal places.) 2. Find a 95% confidence interval for the...
In order to compare the means of two populations, independent random samples of 395 observations are selected from each population, with the results found in the table to the right. Complete parts a through e below. Sample 2 x2 = 5,250 2-210 Sample 1 X,5,279 1-140 a. Use a 95% confidence interval to estimate the difference between the population means (μ1-μ2) . Interpret the confidence The confidence interval is Round to one decimal place as needed.) Interpret the confidence interval....
In order to compare the means of two populations, independent random samples of 400 observations are selected from each population, with the results found in the table to the right. Complete parts a through e below. Sample 1 overbar x = 5,305 s1= 154 Sample 2 overbar x = 5,266 s2 = 199 a. Use a 95% confidence interval to estimate the difference between the population means (mu 1 - mu 2). Interpret the confidence interval. The confidence interval is...
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 =
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 __________.