Section 7.1 Example 2
The Anderson-Darling normality test is used to test if a dataset comes from a population with a normal distribution.
The two hypotheses for the Anderson-Darling test for the normal distribution are :
H0: The data follows the normal d
STAT 2120 Homework #4 Answer Key
Sections 7.2 and 7.3
7.60 a)
Two-Sample T-Test and CI
Sample
N
Mean StDev
1
10 4.100 0.800
2
10
2.90
1.60
SE Mean
0.25
0.51
Difference = mu (1) - mu (2)
Estimate for difference: 1.200
95% CI for difference: (-0.022, 2.422)
STAT 2120 Homework #3 Answer Key
Section 7.1
7.1 a) = = 19.5
b) n-1 = 15
7.2 The standard error would be smaller, as dividing by a larger value yields a smaller number. The
standard
error is = 15.6.
7.3
One-Sample T
N
Mean StDev
16 508.0
78.0
SE Mean
19.5
STAT 2120 Homework #1 Answer Key
Section 6.1 Review
6.1
= = = 22
6.2 two standard deviations or $44
6.3 $44.
6.5 One-Sample Z
The assumed standard deviation = 112.08
N
453
Mean
405.02
SE Mean
5.27
95% CI
(394.70, 415.34)
Assumption/Required Condition: By
Sections 7.2 and 7.3 - Example 4 Write-up
OUTPUT FOR THE FOLLOWING STACKED DATA CODING: GROUP1 = 18-34, GROUP2 =35-50
To create the histograms shown below:
Graph Histogram With Fit OK
Graph variables: Times Multiple Graphs
By variables By variables with g
Sections 7.2 and 7.3 - Example 2 Write-up
It appears that the normality assumption is satisfied for both groups.
Test and CI for Two Variances: Teller 1, Teller 2
Method
Null hypothesis
Alternative hypothesis
Significance level
Sigma(Teller 1) / Sigma(Tel
Sections 7.2 and 7.3 - Example 3 Write-up
It appears that the normality assumption is satisfied for both groups.
a. Can we conclude that, using weight gain as our criterion, Tastee baby food is indeed superior?
Conduct a test using a 5% significance level
Section 7.1 - Part 2 - Class Example Write-ups
Example 4
Comment on graphs: The normality assumption appears to be valid based on both the histogram
and the normal probability plot. However, there is one outlier.
One-Sample T: Orders
Test of mu = 85 vs >
Section 7.1 - Part 2 - Class Example Write-up
Example 3
Comment on graphs: The normality assumption appears to be valid based on the histogram, but
not according to the normal probability plot. The robustness guidelines indicate that with a
sample size of
STAT 2120 Homework #5 Answer Key
Section 8.1
8.1 a) n = 760 b) x = 283; 283 of the banks plan to acquire another bank within five years.
c) = 283/760 = 0.3724
8.2 a) n = 1063 b) x = 223 c) = 263/1063 = 0.2098
8.3 a)
= 0.0175
b) 0.3724 (1.96)(0.0175) 0.372