2b.
Given that,
sample 1
s1^2=48, n1 =16
sample 2
s2^2 =26, n2 =25
null, Ho: σ^2 = σ^2
alternate, H1: σ^2 > σ^2
level of significance, α = 0.05
from standard normal table,right tailed f α/2 =2.108
since our test is right-tailed
we use test statistic fo = s1^1/ s2^2 =48/26 = 1.85
| fo | =1.85
critical value
the value of |f α| at los 0.05 with d.f f(n1-1,n2-1)=f(15,24) is
2.108
we got |fo| =1.846 & | f α | =2.108
make decision
hence value of |fo | < | f α | and here we do not reject
Ho
ANSWERS
---------------
null, Ho: σ^2 = σ^2
alternate, H1: σ^2 > σ^2
test statistic: 1.85
critical value: 2.108
decision: do not reject Ho
we do not have enough evidence to support the claim that first
variance for the first population is higher than second
variance for second population.
2b) The random samples with sizes 14 = 16 and n2 = 25 respectively were taken...
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...
12 marks Let independent random samples of sizes n and n2 be taken respectively from two normal distributions with unknown means 1 and 2 and unknown variances oand o. Denote the two samples by . . ,Jn, and y,... , yn2: Which have means T and T, and sample variances s and s2, respectively (a) 4 marks Show that when of = o2, the likelihood ratio test statistic for testing Ho 12 against H 2 can be written as T2...
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...
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...
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 =
From two normal population assumed to have the same variance, independent random samples of sizes 15 and 19 were drawn. The first sample (n1=15) yielded mean and standard deviation 111.6 and 9.5 respectively, while the second sample (n2=19) gave mean and standard deviation 100.9 and 11.5 respectively. Suppose Ho: mu1 = mu2 Ha: mu1 > mu2 (alpha level = 0.05) (i) Write the rule for rejecting Ho in terms of T-scores. (ii) Compute the T statistic, a p-value for the...
From two normal population assumed to have the same variance, independent random samples of sizes 15 and 19 were drawn. The first sample (n1=15) yielded mean and standard deviation 111.6 and 9.5 respectively, while the second sample (n2=19) gave mean and standard deviation 100.9 and 11.5 respectively. Suppose Ho: mu1 = mu2 Ha: mu1 > mu2 (alpha level = 0.05) (i) Write the rule for rejecting Ho in terms of T-scores. (ii) Compute the T statistic, a p-value for the...
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.
Two independent random samples are taken from a normal population with mean 40 and variance 16. The sample sizes are 5 and 20, and the corresponding sample means are denoted X1 and X2. Determine 1. EX1 - X2) 2. Var (X1 - X2)