independent random samples selected from two normal populations
produced the following sample means and standard deviations. sample
1: n1= 17, x1= 5.4, s1= 3.4
sample 2: n2 =12, x2 = 7.9, s2= 4.8
a. assuming equal variances, conduct the test ho: (m1-m2) is
equal to 0, against the ha: (m1-m2) isn't equal to 0 using alpha =
.05
b. find and interpret the 95% confidence interval (m1-m2).
Independent random samples selected from two normal populations
produced the following sample means and standard deviations.
Sample 1
Sample 2
n1 = 14
n2 = 11
1 = 7.1
2 = 8.4
s1 = 2.3
s2 = 2.9
Find and interpret the 95% confidence interval
for
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¯1=58.9,x¯2=74.7,s1=5.5s2=10.1 n 1 =37, x ¯ 1 =58.9, s
1 =5.5 n 2 =44, x ¯ 2 =74.7, s 2 =10.1 Find a 95.5% confidence
interval for the difference μ1−μ2 μ 1 − μ 2 of the means, assuming
equal population variances. Confidence Interval
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=39,n2=48,x¯1=52.5,x¯2=77.5,s1=5s2=11 Find a 97.5% confidence
interval for the difference μ1−μ2 of the means, assuming equal
population variances. Confidence Interval =
In order to compare the means of two populations, independent
random samples are selected from each population, with the results
shown in the table below. Use these data to construct a 98%
confidence interval for the difference in the two population
means.
Sample 1
Sample 2
Sample size
500
400
Sample mean
5,280
5,240
Sample standard dev.
150
200
Two random samples are selected from two independent
populations. A summary of the sample sizes, sample means, and
sample standard deviations is given below:
n1=43, x¯1=59.1, ,s1=5.9
n2=40, x¯2=72.6, s2=11
Find a 99% confidence interval for the difference μ1−μ2 of the
means, assuming equal population variances.
_________<μ1−μ2<____________
Consider independent random samples from two populations that
are normal or approximately normal, or the case in which both
sample sizes are at least 30. Then, if σ1 and
σ2 are unknown but we have reason to believe
that σ1 = σ2, we can pool
the standard deviations. Using sample sizes n1
and n2, the sample test statistic
x1 − x2 has a Student's
t distribution where
t =
x1 − x2
s
1
n1
+
1
n2
with degrees...
Two independent random samples were selected from two normally
distributed populations with means and variances (μ1,σ21) and
(μ2,σ22). The sample sizes, means and variances are shown in the
following table.
Sample 1 n1 = 13 x̄1 = 18.2 s21 = 75.3
Sample 2 n2 = 14 x̄2 = 17.1 s2= 61.3
(a). Test H0 : σ12 = σ2against Ha : σ12 ̸= σ2. Use α = 0.05.
Clearly show the 4 steps.
(b). TestH0 :μ1 −μ2 =0againstHa :μ1 −μ2 >0....
Independent random samples, each containing 60 observations,
were selected from two populations. The samples from populations 1
and 2 produced 37 and 30 successes, respectively.
Test H0:(p1−p2)=0 against Ha:(p1−p2)≠0. Use α=0.05.
(a) The test statistic is
(b) The P-value is
(c) The final conclusion is
A. We can reject the null hypothesis that
(p1−p2)=0 and conclude that (p1−p2)≠0.
B. There is not sufficient evidence to reject the
null hypothesis that (p1−p2)=0.
Independent random samples, each containing 60 observations,
were selected from two populations. The samples from populations 1
and 2 produced 23 and 13 successes, respectively.
Test H0:(p1−p2)=0H0:(p1−p2)=0 against
Ha:(p1−p2)>0Ha:(p1−p2)>0. Use α=0.03α=0.03
(a) The test statistic is
(b) The P-value is