Question

An advertising firm states that 27% of households will buy something on the internet next year....

An advertising firm states that 27% of households will buy something on the internet next year. how large a sample is needed to be 92% confident that this proportion is within 5% of true proportion.

answer is 242

Math   Statistics-And-Probability   
0 0
Add a commentTranscribed image text
Next >

Homework Answers

Answer #1

Solution :

Given that,

= 0.27

1 - = 0.73

margin of error = E = 0.05

At 92% confidence level the z is ,

= 1 - 92% = 1 - 0.92 = 0.08

/ 2 = 0.08 / 2 = 0.04

Z/2 = Z0.04 = 1.751

sample size = n = (Z / 2 / E )2 * * (1 - )

= (1.751 / 0.05)2 * 0.27*0.73

= 241.72

sample size = 242

The answer is 242

0 0
Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Log In

Sign Up

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
The Academy of Orthopedic Surgeons states that 80% of women wear shoes that are too small...
The Academy of Orthopedic Surgeons states that 80% of women wear shoes that are too small for their feet. A researcher wants to be 95% confident that this proportion is within 3% of the true proportion. How large a sample is necessary?
A report states that 44% of home owners had a vegetable garden. How large a sample...
A report states that 44% of home owners had a vegetable garden. How large a sample is needed to estimate the true proportion of home owners who have vegetable gardens to within 6% with 95% confidence? A. 132 B. 66 C. 263 D. 526
In a random sample of 500 residential units, it is found that 114 of them are...
In a random sample of 500 residential units, it is found that 114 of them are insured by a homeownership insurance scheme. a Construct a 90% confidence interval for the true proportion of residential units that are insured by a homeownership insurance scheme. b Utilizing the information provided by the answer in part (a) about the possible range of the true population proportion, determine how large a sample is needed if you wish to be 99% confident that the sample...
An advertising firm plans to have a sample of individuals view a commercial on a ‘‘sunscreen...
An advertising firm plans to have a sample of individuals view a commercial on a ‘‘sunscreen pill” that one can swallow to provide mild SPF protection throughout the day. After viewing the commercial, each individual will be asked if he/she would consider buying the product. How many individuals should the firm sample to estimate the proportion who would consider buying the product to within a plus-or-minus 4 % margin of error with 90% confidence? Round your answer up to the...
1.) You want to obtain a sample to estimate a population mean. Based on previous evidence,...
1.) You want to obtain a sample to estimate a population mean. Based on previous evidence, you believe the population standard deviation is σ=49.3σ=49.3. You would like to be 99% confident that you estimate is within 5 of the true population mean. How large of a sample size is required? n =   Note: Use z-scores rounded to 3 decimal places in your calculations. 2.) You want to obtain a sample to estimate a population mean. Based on previous evidence, you...
an electrical firm manufactures light bulbs that have a length of life that is approximately normally...
an electrical firm manufactures light bulbs that have a length of life that is approximately normally distributed with a standard deviation of 40 hours. the firm claims that the mean life of the light bulb is 800 hrs a?if a sample of 30 light bulbs were tested to failure and had an avg life of 780 hours, find 90% confidence interval on the mean b) based on this confidence interval, would you be able to validate the claimed mean life...
A biotechnology firm is planning its investment strategy for future products and research labs. A poll...
A biotechnology firm is planning its investment strategy for future products and research labs. A poll found that 5 ​% of a random sample of 1047 adults approved of attempts to clone a human. Use this information to complete parts a through e. ​a) Find the margin of error for this poll if we want 99 ​% confidence in our estimate of the percent of adults who approve of cloning humans. MEequals 0.017 ​(Round to three decimal places as​ needed.)...
A Pew Internet poll asked cell phone owners about how they used their cell phones. One...
A Pew Internet poll asked cell phone owners about how they used their cell phones. One question asked whether or not during the past 30 days they had used their phone while in a store to call a friend or family member for advice about a purchase they were considering. The poll surveyed 1003 adults living in the United States by telephone. Of these, 462 responded that they had used their cell phone while in a store within the last...
A consumer advocacy group published a study of labeling of seafood sold in three U.S. states....
A consumer advocacy group published a study of labeling of seafood sold in three U.S. states. The group purchased 226 pieces of seafood from various kinds of food stores and restaurants in the three states and genetically compared the pieces to standard gene fragments that can identify the species. The study found that 11 of the 26​ "red snapper" packages tested were a different kind of fish. Assume that the study used a simple random sample. Complete parts b through...
you want to rent an unfirnished one bedroom flat in china , next year . the...
you want to rent an unfirnished one bedroom flat in china , next year . the mean monthly rent for a random sample of 50 flats advertised on a website is $500. assume a population standard deviation of 100 a) construct a 95% confidence interval b) how large a sample of one bedroom flat above would be needed to estimate the population mean within plus or minus $20 with 95% confidence
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT