Question

Independent random samples were selected from two quantitative populations, with sample sizes, means, and standard deviations given below. n1 = n2 = 80, x1 = 125.3, x2 = 123.6, s1 = 5.7, s2 = 6.7

Construct a 95% confidence interval for the difference in the population means (μ1 − μ2). (Round your answers to two decimal places.)

Find a point estimate for the difference in the population means.

Calculate the margin of error. (Round your answer to two decimal places.)

Answer #1

The statistical software output for this problem is:

Hence,

95% confidence interval will be:

(-**0.24, 3.64**)

Point estimate = Sample diff = **1.7**

Margin of error = (3.64 + 0.24)/2 = **1.94**

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=41, n2=44, x¯1=52.3, x¯2=77.3, s1=6 s2=10.8
Find a 96.5% confidence interval for the difference μ1−μ2 of the
means, assuming equal population variances.
Confidence Interval =

Two samples are taken with the following sample means, sizes,
and standard deviations
¯x1 = 21 ¯x2 = 29
n1 = 58 n2 = 56
s1 = 4 s2 = 3
Find a 87% confidence interval, round answers to the nearest
hundredth.
< μ1-μ2 <

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=36,x¯1=56.5,x¯2=75.3,s1=5.3s2=10.7n1=51,x¯1=56.5,s1=5.3n2=36,x¯2=75.3,s2=10.7
Find a 97.5% confidence interval for the difference μ1−μ2μ1−μ2
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=40,x¯1=50.3,x¯2=73.8,s1=6s2=6.1
Find a 98% confidence interval for the difference μ1−μ2 of the
population means, assuming equal population variances.

Two samples are taken with the following sample means, sizes,
and standard deviations
x¯1 = 30 x¯2 = 33
n1 = 48 n2 = 45
s1 = 4 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.
_____< μ1−μ2 < ______

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=45,n2=40,x¯1=50.7,x¯2=71.9,s1=5.4s2=10.6 n 1 =45, x ¯ 1 =50.7, s
1 =5.4 n 2 =40, x ¯ 2 =71.9, s 2 =10.6
Find a 92.5% confidence interval for the difference μ1−μ2 μ 1 −
μ 2 of the means, assuming equal population variances.

Independent random samples selected from two normal populations
produced the following sample means and standard deviations.
Sample 1 Sample 2
n1 = 15 n2 = 11
x1 = 7.1 x2= 9.2
s1 = 2.3 s2 = 2.8
Find the 80% Confidence Interval for the difference in the
population means of Sample 1 and 2.
Circle the correct conclusion below:
A) The result suggests that there is no significant difference
between the means.
B) The result suggests that Sample 1 population...

1. Two independent samples are taken from two
distinct populations whichproduce sample means, standard deviations
as ̄x1= 104.6, ̄x2= 92.9,s1= 4.8,s2= 6.9,n1= 26,n2= 19.If we use
min(n1−1,n2−1) as the d.f., what t critical value would you usein
constructing a 90% confidence interval
forμ1−μ2?a). 2.101; b) 1.734; c) 1.708; d) 1.645

Independent random samples were selected from populations 1 and
2. The sample sizes, means, and variances are as follows.
Population
1
2
Sample Size
30
64
Sample Mean
11.4
6.9
Sample Variance
1.37
4.15
(a) Find a 95% confidence interval for estimating the difference
in the population means (μ1 −
μ2). (Round your answers to two decimal
places.)
to

The following results are for independent random samples taken
from two populations.
Sample 1
Sample 2
n1 = 20
n2 = 30
x1 = 22.8
x2 = 20.1
s1 = 2.6
s2 = 4.6
(a)
What is the point estimate of the difference between the two
population means? (Use
x1 − x2.
)
(b)
What is the degrees of freedom for the t distribution?
(Round your answer down to the nearest integer.)
(c)
At 95% confidence, what is the margin...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 2 minutes ago

asked 9 minutes ago

asked 9 minutes ago

asked 14 minutes ago

asked 20 minutes ago

asked 31 minutes ago

asked 23 minutes ago

asked 23 minutes ago

asked 33 minutes ago

asked 36 minutes ago

asked 37 minutes ago

asked 1 hour ago