Question

A manufacturing company is purchasing metal pipes of standard length from two different suppliers, ABC and...

A manufacturing company is purchasing metal pipes of standard length from two different suppliers, ABC and XYZ. In the past two months there are increasing complaints by the Production Manager that delivery times by ABC present higher variability in comparison to the delivery times by XYZ. The Production Manager is worried that this variability will make it harder to efficiently schedule the production process. Does the sample data indicate a statistically significant difference at the 5% level? Justify your answer. Based on your conclusion, which possible error could you be making? Type I or type II error?

Delivery Times(in Hours) by Suppliers ABC and XYZ on Selected Orders
Order Supplier ABC Order Supplier XYZ
1 35 1 19
2 26 2 23
3 26 3 22
4 30 4 21
5 25 5 26
6 20 6 24
7 24 7 23
8 25 8 17
9 19 9 24
10 27 10 21
11 29 11 28
12 25 12 30
13 12 13 20
14 20 14 34
15 22 15 23
16 17 16 26
17 21 17 28
18 16 18 28
19 32 19 26
20 23 20 30
21 29 21 36
22 22 22 22
23 12 23 20
24 28 24 22
25 24 25 21
26 27
27 18

Homework Answers

Answer #1

Variance of ABC, s12 = 31.57

Variance of XYZ, s22 = 21.51

Level of significance = 0.05

Degrees of freedom for ABC: df1 = n1-1 = 27-1 = 26

Degrees of freedom for XYZ: df1 = n2-1 = 25-1 = 24

H0: σ12 = σ22, Delivery times by ABC do not present higher variability in comparison to the delivery times by XYZ

H1: σ12 > σ22, Delivery times by ABC present higher variability in comparison to the delivery times by XYZ

Test statistic: F = s12 / s22 = 31.57/21.51 = 1.47

Critical value (Using Excel function F.INV.RT(probability,df1,df2)) = F.INV.RT(0.05,26,24) = 1.97

Since test statistic is less than critical value, we reject the null hypothesis and conclude that σ12 > σ22.

So, delivery times by ABC present higher variability in comparison to the delivery times by XYZ.

Type 2 Error: Accepting an alternate hypothesis that is false

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
A manufacturing company is purchasing metal pipes of standard length from two different suppliers, ABC and...
A manufacturing company is purchasing metal pipes of standard length from two different suppliers, ABC and XYZ. In the past two months there are increasing complaints by the Production Manager that delivery times by ABC present higher variability in comparison to the delivery times by XYZ. The Production Manager is worried that this variability will make it harder to efficiently schedule the production process. If the variance of XYZ remains unchanged, what should be the variance of ABC in order...
A manufacturing company is purchasing metal pipes of standard length from two different suppliers, ABC and...
A manufacturing company is purchasing metal pipes of standard length from two different suppliers, ABC and XYZ. In the past two months there are increasing complaints by the Production Manager that delivery times by ABC present higher variability in comparison to the delivery times by XYZ. The Production Manager is worried that this variability will make it harder to efficiently schedule the production process. Does the sample data indicate a statistically significant difference at the 5% level? Justify your answer....
A study was conducted to see if students’ writing skills continue to improve as the academic...
A study was conducted to see if students’ writing skills continue to improve as the academic year progresses. English 101 students were asked to write essays throughout the year in September, December, March and June. The scores were compared to see if there is any improvement in this one-year course. Was there a significant improvement? The appropriate test for this problem is: one-way ANOVA repeated measurements Student September December March June 1 17 23 21 24 2 25 21 21...
The results of a sample of 372 subscribers toWiredmagazine shows the time spent using the Internet...
The results of a sample of 372 subscribers toWiredmagazine shows the time spent using the Internet during the week. Previous surveys have revealed that the population standard deviation is 10.95 hours. The sample data can be found in the Excel test data file. What is the probability that another sample of 372 subscribers spends less than 19.00 hours per week using the Internet? Develop a 95% confidence interval for the population mean If the editors of Wiredwanted to have the...
6. Using the class data (see Blackboard file - "Class Survey Data - PSS-10 and GAS")...
6. Using the class data (see Blackboard file - "Class Survey Data - PSS-10 and GAS") calculate the correlation between the GAS – Goal disengagement and the GAS – Goal reengagement scores. Write the results in a statistical statement. 7. Using the class data calculate the correlation between the GAS – Goal disengagement and the PSS-10 scores. Write the results in a statistical statement. 8. Using the class data calculate the correlation between the GAS – Goal reengagement scores and...
____________________________________________ The results of a sample of 372 subscribers to Wired magazine shows the time spent...
____________________________________________ The results of a sample of 372 subscribers to Wired magazine shows the time spent using the Internet during the week. Previous surveys have revealed that the population standard deviation is 10.95 hours. The sample data can be found in the Excel test data file. What is the probability that another sample of 372 subscribers spends less than 19.00 hours per week using the Internet? ____________________________________________ Develop a 95% confidence interval for the population mean ____________________________________________ If the editors...
The Department of Energy provides fuel economy ratings for all cars and light trucks sold in...
The Department of Energy provides fuel economy ratings for all cars and light trucks sold in the United States. Offered are the estimated miles per gallon for city driving for the 186 cars classified as midsize in 2016, arranged in increasing order: 11 11 11 12 13 13 13 14 14 14 14 14 15 15 15 15 15 15 16 16 16 16 16 16 16 16 16 16 16 16 16 17 17 17 17 17 17 18...
Dataset: Husband   Wife 53   50 38   34 46   44 30   36 31   23 26   31 29  ...
Dataset: Husband   Wife 53   50 38   34 46   44 30   36 31   23 26   31 29   25 48   51 65   46 29   26 28   23 29   32 25   22 22   21 21   24 43   50 24   27 38   33 33   26 35   29 40   29 27   25 27   24 49   38 48   39 27   27 26   24 40   34 35   37 21   26 32   39 30   28 60   52 36   40 25   23 66   55 52   34 41   40 43  ...
Data set for ages of students in stats class: 17, 18, 18, 18, 18, 18, 18,...
Data set for ages of students in stats class: 17, 18, 18, 18, 18, 18, 18, 18, 18, 18, 18, 19, 19, 19, 19,19, 20, 20, 20, 21, 21, 21, 21, 21, 21, 22, 22, 22, 22, 23, 23, 23, 23, 24, 25, 25, 25, 26, 26, 27, 28, 28, 28, 28, 29, 29, 32, 36, 42 1) Compute the 5-number summary and create a modified box-plot, using the inner-quartile range to identify any outliers.
A company has the following returns over the past 30 months: Month Ret.(%) Month Ret.(%) Month...
A company has the following returns over the past 30 months: Month Ret.(%) Month Ret.(%) Month Ret.(%) 1) 3 11   -3 21 -1 2) -16 12 -2 22 -24 3) 31 13 -8 23 -14 4) 33 14 2 24 -19 5) -23 15 35 25 -19 6) -17 16 11 26 33 7) 8 17 -20 27 -18    8) -19 18 15 28 23 9) -13 19 -12 29 6 10 -17 20 17 30 5 What is...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT
Active Questions
  • The following sample observations were randomly selected. (Round intermediate calculations and final answers to 2 decimal...
    asked 6 minutes ago
  • what type of graph is best suitable for data obtained from customer ratings. The ratings are...
    asked 9 minutes ago
  • Determine the cumulative 15-year 18 kip ESAL’s in the design lane for 2-lane highway for the...
    asked 17 minutes ago
  • Q: Dr.Grimace, the evil dentist, is trying to find out if his patients suffer from periodontal...
    asked 17 minutes ago
  • After collecting data on 19283 dogs, you find that male vallhunds have an average weight of...
    asked 19 minutes ago
  • Research Target Corporation and assess your satisfaction with the company you researched and make recommendations about...
    asked 20 minutes ago
  • Evidence suggests that 70% of FSU students like turtles. Suppose we randomly sampled 15 FSU students....
    asked 20 minutes ago
  • Ulrich challenges the appropriateness of the nearly universal symbolism of the spinning wheel as the marker...
    asked 21 minutes ago
  • Differential Equations: Please try to computer type, if not possible be clear and organize. Thank you...
    asked 21 minutes ago
  • In your opinion, what are the three (3) most important benefits an employer can give to...
    asked 27 minutes ago
  • In a test of the effectiveness of garlic for lowering​ cholesterol, 81 subjects were treated with...
    asked 29 minutes ago
  • How does the 95% confidence interval correspond to the reported conclusion at a 0.05 significance level?...
    asked 30 minutes ago