The variance in a production process is an important measure of the quality of the process. A large variance often signals an opportunity for improvement in the process by finding ways to reduce the process variance. Machine 1 Machine 2 2.95 3.45 3.50 3.75 3.48 3.26 3.33 3.20 3.22 3.30 3.34 3.28 3.29 3.25 3.30 | 3.26 3.16 3.20 3.22| 3.38 | 3.90 3.36 3.25 3.28 3.38 3.34 3.35 3.19 3.35 3.05 3.36 3.28 3.20 3.22 2.98 3.45 3.70 3.34 3.18 3.35 3.30 3.28 3.30 3.20 3.16 3.33 3.12 Conduct a statistical test to determine whether there is a significant difference between the variances in the bag weights for two machines. Use a 0.05 level of significance. What is your conclusion? State the null and alternative hypotheses. Hoi o,? > a,? Hoio,? = 02
Inverse Normal Distribution
The method used for finding the corresponding z-critical value in a normal distribution using the known probability is said to be an inverse normal distribution. The inverse normal distribution is a continuous probability distribution with a family of two parameters.
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It is a descriptive summary of a data set. It can be defined by using some of the measures. The central tendencies do not provide information regarding individual data from the dataset. However, they give a summary of the data set. The central tendency or measure of central tendency is a central or typical value for a probability distribution.
Z-Scores
A z-score is a unit of measurement used in statistics to describe the position of a raw score in terms of its distance from the mean, measured with reference to standard deviation from the mean. Z-scores are useful in statistics because they allow comparison between two scores that belong to different normal distributions.
![Which machine, if either, provides the greater opportunity for quality improvements?
Machine 1 offers the best opportunity for process quality improvements.
Machine 2 offers the best opportunity for process quality improvements.
Neither machine offers an opportunity for process quality improvements.](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F6fccbe0e-690a-4599-ae28-c1fea38612a2%2Fde542b4a-6855-4407-9245-90e7fe8df866%2Fq6khavo_processed.png&w=3840&q=75)
![The variance in a production process is an important measure of the quality of the process. A large variance often signals an opportunity for improvement in the process by finding ways to reduce the
process variance.
Machine 1
Machine 2
2.95
3.45
3.50
3.75
3.48
3.26
3.33
3.20
3.22
3.30
3.34
3.28
3.29
3.25
3.30
3.26
3.16
3.20
3.22
3.38
3.90
3.36
3.25
3.28
3.38
3.34
3.35
3.19
3.35
3.05
3.36
3.28
3.20
3.22
2.98
3.45
3.70
3.34
3.18
3.35
3.30
3.28
3.30
3.20
3.16
3.33
3.12
Conduct a statistical test to determine whether there is a significant difference between the variances in the bag weights for two machines. Use a 0.05 level of significance. What is your conclusion?
State the null and alternative hypotheses.
2
Ho: 01 < 02
Ha: 01
2
02
2
2
> 02
2
2
2
2
Ho: 01
02
Ha: 01
= 02
2
Ho: 01
02
Ha: 01
+ 02
Find the value of the test statistic. (Round your answer to two decimal places.)
Find the p-value. (Round your answer to four decimal places.)
p-value
State your conclusion.
Do not reject Ho. We can conclude that the process variances are significantly different.
0'
Reject Ho. We can conclude that the process variances are significantly different.
Do not reject Ho. We cannot conclude that the process variances are significantly different.
Reject Ho. We cannot conclude that the process variances are significantly different.
O O](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F6fccbe0e-690a-4599-ae28-c1fea38612a2%2Fde542b4a-6855-4407-9245-90e7fe8df866%2F9sutq8_processed.png&w=3840&q=75)
![](/static/compass_v2/shared-icons/check-mark.png)
Level of significance = = 0.05
Given data is,
Machine 1 | Machine 2 |
2.95 | 3.22 |
3.45 | 3.3 |
3.5 | 3.34 |
3.75 | 3.28 |
3.48 | 3.29 |
3.26 | 3.25 |
3.33 | 3.3 |
3.2 | 3.26 |
3.16 | 3.38 |
3.2 | 3.3 |
3.22 | 3.35 |
3.38 | 3.19 |
3.9 | 3.35 |
3.36 | 3.05 |
3.25 | 3.36 |
3.28 | 3.28 |
3.2 | 3.3 |
3.2 | 3.28 |
2.98 | 3.3 |
3.45 | 3.2 |
3.7 | 3.16 |
3.34 | 3.33 |
3.18 | |
3.35 | |
3.12 |
We have to conduct a statistical test to determine whether there is significant difference between the variances in the bag weights of two machines.
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