Question

suppose the consumer research center researchers wanted to be 95% confident that teir estimate is within...

suppose the consumer research center researchers wanted to be 95% confident that teir estimate is within 2% of the true population proportion. how large a sample should they choose for their survey? the preliminary estimate was 29%

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

Homework Answers

Answer #1

Solution :

Given that,

= 29%=0.29

1 - = 1 - 0. 29= 0.71

margin of error = E = 2% = 0.02

At 95% confidence level the z is ,

= 1 - 95% = 1 - 0.95 = 0.05

/ 2 = 0.05 / 2 = 0.025

Z/2 = Z0.025 = 1.96

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

= (1.96 / 0.02)2 * 0.29* 0.71

= 1977.4636

Sample size =1978

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
18. A researcher wishes to be 95% confident that her estimate of the true proportion of...
18. A researcher wishes to be 95% confident that her estimate of the true proportion of individuals who travel overseas is within 3% of the true proportion. a) Find the sample necessary if, in a prior study, a sample of 200 people showed that 40 traveled overseas last year. b) b) If no estimate of the sample proportion is available, how large should the sample be?
A researcher wishes to​ estimate, with 95​% ​confidence, the population proportion of adults who are confident...
A researcher wishes to​ estimate, with 95​% ​confidence, the population proportion of adults who are confident with their​ country's banking system. His estimate must be accurate within 4​% of the population proportion. ​(a) No preliminary estimate is available. Find the minimum sample size needed. ​(b) Find the minimum sample size​ needed, using a prior study that found that 28​% of the respondents said they are confident with their​ country's banking system. ​(c) Compare the results from parts ​(a) and ​(b).
You want to obtain a sample to estimate a population proportion. At this point in time,...
You want to obtain a sample to estimate a population proportion. At this point in time, you have no reasonable preliminary estimation for the population proportion. You would like to be 95% confident that you estimate is within 5% of the true population proportion. How large of a sample size is required?
You want to obtain a sample to estimate a population proportion. At this point in time,...
You want to obtain a sample to estimate a population proportion. At this point in time, you have no reasonable preliminary estimation for the population proportion. You would like to be 95% confident that you estimate is within 1.5% of the true population proportion. How large of a sample size is required? n =
You want to obtain a sample to estimate a population proportion. At this point in time,...
You want to obtain a sample to estimate a population proportion. At this point in time, you have no reasonable preliminary estimation for the population proportion. You would like to be 95% confident that you estimate is within 3.5% of the true population proportion. How large of a sample size is required? n =  
3) In a Pew Research Center report from January 2015, 37% of American adults say that...
3) In a Pew Research Center report from January 2015, 37% of American adults say that genetically modified (GM) foods are generally safe to eat. The margin of error for the 95% confidence interval is 3.1%. What does this margin of error tell you about the results of the survey? Group of answer choices We are confident that the population proportion is within 3.1% of the sample proportion of 37%. We are confident that 95% of the responses are within...
A researcher wishes to? estimate, with 95?% ?confidence, the population proportion of adults who are confident...
A researcher wishes to? estimate, with 95?% ?confidence, the population proportion of adults who are confident with their? country's banking system. His estimate must be accurate within 3?% of the population proportion. ?(a) No preliminary estimate is available. Find the minimum sample size needed. ?(b) Find the minimum sample size? needed, using a prior study that found that 22?% of the respondents said they are confident with their? country's banking system. ?(c) Compare the results from parts ?(a) and ?(b)....
You want to obtain a sample to estimate a population proportion. At this point in time,...
You want to obtain a sample to estimate a population proportion. At this point in time, you have no reasonable preliminary estimation for the population proportion. You would like to be 80% confident that you estimate is within 2% of the true population proportion. How large of a sample size is required?
Determine the required sample size if you want to be 99% confident that the sample proportion...
Determine the required sample size if you want to be 99% confident that the sample proportion is within 2% of the population proportion if no preliminary estimate of the true population is available.
A research firm wants to be 90 percent confident that a population percentage of people who...
A research firm wants to be 90 percent confident that a population percentage of people who prefer chocolate ice cream over vanilla that has been estimated to be within 3 percentage points. Suppose that a study designed to collect new data on search engine preferences uses a preliminary estimate of the proportion of people who prefer chocolate over vanilla as 56 percent. A) How large a sample must be taken to estimate the proportion of people who prefer chocolate over...
ADVERTISEMENT
Need Online Homework Help?

Get Answers For Free
Most questions answered within 1 hours.

Ask a Question
ADVERTISEMENT