Question

Cement is one of the ingredients of concrete. Concrete is produced in “ready-mixed concrete plants.” Few...

Cement is one of the ingredients of concrete. Concrete is produced in “ready-mixed concrete plants.” Few years ago, a new type of cement entered the market. We want to find out what portion of the ready-mixed concrete plants use this new cement. Assume that there are 5,000 plants in the US. We select 100 plants and ask their managers if they use the new cement. We find that 20 of them use the new cement. For a confidence level of 95%, find the confidence interval for the percentage of ready-mixed concrete plants in the US that use the new cement

Homework Answers

Answer #1

We need to construct the 95% confidence interval for the population proportion. We have been provided with the following information about the number of favorable cases:

Favorable Cases X = 20
Sample Size N = 100

The sample proportion is computed as follows, based on the sample size N = 100 and the number of favorable cases X = 20 :

The critical value for α=0.05 is z_c = 1.96. The corresponding confidence interval is computed as shown below:

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
Cement is one of the ingredients of concrete. Concrete is produced in “ready-mixed concrete plants.” Few...
Cement is one of the ingredients of concrete. Concrete is produced in “ready-mixed concrete plants.” Few years ago, a new type of cement entered the market. We want to find out what portion of the ready-mixed concrete plants use this new cement. Assume that there are 5,000 plants in the US. We select 100 plants and ask their managers if they use the new cement. We find that 20 of them use the new cement. For a confidence level of...
Cement is one of the ingredients of concrete. Concrete is produced in “ready-mixed concrete plants.” Few...
Cement is one of the ingredients of concrete. Concrete is produced in “ready-mixed concrete plants.” Few years ago, a new type of cement entered the market. We want to find out what portion of the ready-mixed concrete plants use this new cement. Assume that there are 5,000 plants in the US. We select 100 plants and ask their managers if they use the new cement. We find that 20 of them use the new cement. For a confidence level of...
Cement is one of the ingredients of concrete. Concrete is produced in “ready-mixed concrete plants.” Few...
Cement is one of the ingredients of concrete. Concrete is produced in “ready-mixed concrete plants.” Few years ago, a new type of cement entered the market. We want to find out what portion of the ready-mixed concrete plants use this new cement. Assume that there are 5,000 plants in the US. We select 100 plants and ask their managers if they use the new cement. We find that 20 of them use the new cement. For a confidence level of...
Gary Stevens and Mary James are production managers in the Consumer Electronics Division of General Electronics...
Gary Stevens and Mary James are production managers in the Consumer Electronics Division of General Electronics Company, which has several dozen plants scattered in locations throughout the world. Mary manages the plant located in Des Moines, Iowa, while Gary manages the plant in El Segundo, California. Production managers are paid a salary and get an additional bonus equal to 5% of their base salary if the entire division meets or exceeds its target profits for the year. The bonus is...
This is a true story sent to me just a few days ago from a student...
This is a true story sent to me just a few days ago from a student who took my class in 2017. She has since graduated and is working for a company which makes oil emulsions for other customers to use in mixture with another product. Due to the uniqueness of the student's company product she cannot name it or divulge its makeup. Nor can she name the customer company and how they use the emulsion. She emailed me the...
Gary Stevens and Mary James are production managers in the Consumer Electronics Division of General Electronics...
Gary Stevens and Mary James are production managers in the Consumer Electronics Division of General Electronics Company, which has several dozen plants scattered in locations throughout the world. Mary manages the plant located in Des Moines, Iowa, while Gary manages the plant in El Segundo, California. Production managers are paid a salary and get an additional bonus equal to 10% of their base salary if the entire division meets or exceeds its target profits for the year. The bonus is...
CASE 4–20 Ethics and the Manager, Understanding the Impact of Percentage Completion on Profit—Weighted-Average Method [Course...
CASE 4–20 Ethics and the Manager, Understanding the Impact of Percentage Completion on Profit—Weighted-Average Method [Course Objective B] Gary Stevens and Mary James are production managers in the Consumer Electronics Division of General Electronics Company, which has several dozen plants scattered in locations throughout the world. Mary manages the plant located in Des Moines, Iowa, while Gary manages the plant in El Segundo, California. Production managers are paid a salary and get an additional bonus equal to 5% of their...
Read the LDC Cloud Systems Case Study and answer the question below: THE EMAIL The email...
Read the LDC Cloud Systems Case Study and answer the question below: THE EMAIL The email had been sent from one mid-level accounting manager at headquarters to another about six months earlier. The message read: Bill, here are the accounting issues I mentioned, and as you know, some of these go back a ways. The data that supports these accounts are not always clear and keep changing, and we are not sure what the correct accounting treatment is for these...
As you saw from the lab PowerPoint slides last week, you will be doing a research...
As you saw from the lab PowerPoint slides last week, you will be doing a research study looking at ‘Aggression Priming” for your first paper. For this week’s discussion, I want you to discuss with your group what you think this study is about. What is the hypothesis? What theory does it come from? What do you predict will happen (do you expect something different than the hypothesis in the researcher instructions? If so, what and why?)? Do you think...
Consumerization of Technology at IFG3 “There’s good news and bad news,” Josh Novak reported to the...
Consumerization of Technology at IFG3 “There’s good news and bad news,” Josh Novak reported to the assembled IT management team at their monthly status meeting. “The good news is that our social media traffic is up 3000% in the past two years. Our new interactive website, Facebook presence, and our U-Tube and couponing promotions have been highly successful in driving awareness of our ‘Nature’s Glow’ brand and are very popular with our target demographic—the under-30s. Unfortunately, the bad news is...