A medical researcher wants to construct a 99% confidence interval for the proportion of knee replacement...

A medical researcher wants to construct a 99% confidence interval for the proportion of knee replacement surgeries that result in complications. An article in the Journal of Bone and Joint Surgery suggested that approximately 8% of such operations result in complications. Using this estimate, what sample size is needed so that the confidence interval will have a margin of error of 0.047 ? Write only an integer as your answer.

Solutions

Expert Solution

Sample size estimation for proportion

Preliminary estimate for proportion (Known) =    0.08
Margin of error =E=0.047
Level of significance =1-0.99=   0.01
Z critical value is (by using Z table)=2.58

Sample size
$n=\left [ \hat{p} (1-\hat{p})\right ]\left [ \frac{Z}{E} \right ]^2$

=221.06

Therefore, sample size approximately will be 222

orchestra answered 2 years ago

Next > < Previous

Related Solutions

Construct a 99% confidence interval to estimate the population proportion with a sample proportion equal to...

Construct a 99% confidence interval to estimate the population proportion with a sample proportion equal to 0.90 and a sample size equal to 250. ------A 99% confidence interval estimates that the population proportion is between a lower limit of ___ and an upper limit of ___. ????????

Construct a 99% confidence interval to estimate the population proportion with a sample proportion equal to...

Construct a 99% confidence interval to estimate the population proportion with a sample proportion equal to 0.50 and a sample size equal to 200. LOADING... Click the icon to view a portion of the Cumulative Probabilities for the Standard Normal Distribution table. A 99% confidence interval estimates that the population proportion is between a lower limit of nothing and an upper limit of nothing. (Round to three decimal places as needed.)

1a. Construct a 99% confidence interval for proportion of obese people in the population the above...

1a. Construct a 99% confidence interval for proportion of obese people in the population the above sample was taken. (BMI>29.5 is counted as ob 1.b Is there any evidence to show there is difference between proportion of smokers between male and female? Apply appropriate test with alpha=0.05. USE R AND SHOW CODES Male=1, Female=0 Smoker=1, Nonsmoker=0 DATA sex age currentSmoker BMI 1 39 0 26.97 0 46 0 28.73 1 48 1 25.34 0 61 1 28.58 0 46 1...

How's the economy? A pollster wants to construct a 99.5% confidence interval for the proportion of...

How's the economy? A pollster wants to construct a 99.5% confidence interval for the proportion of adults who believe that economic conditions are getting better. (a) A poll taken in July 2010 estimates this proportion to be 0.3 Using this estimate, what sample size is needed so that the confidence interval will have a margin of error of 0.02? A sample of adults is needed to obtain a 99.5% confidence interval with a margin of error of 0.02 . B....

3) Kim wants to determine a 99 percent confidence interval for the true proportion p of...

3) Kim wants to determine a 99 percent confidence interval for the true proportion p of high school students in the area who attend their home basketball games. Out of ?n randomly selected students she finds that that exactly half attend their home basketball games. About how large would ?n have to be to get a margin of error less than 0.01 for p? [Use the values for z* from a z-table or t-table, and round to the smallest integer...

A pollster wants to construct a 95% confidence interval for the proportion of all U.S. adults...

A pollster wants to construct a 95% confidence interval for the proportion of all U.S. adults who believe that economic conditions are getting better under President Donald Trump. How large a sample should the pollster take so that the estimate is within 3.0% of the true population proportion? [4]

Call me: A sociologist wants to construct a 98% confidence interval for the proportion of children...

Call me: A sociologist wants to construct a 98% confidence interval for the proportion of children aged 8-10 living in New York who own a cell phone. (a) A survey by the National Consumers League taken in 2012 estimated the nationwide proportion to be 0.28. Using this estimate, what sample size is needed so that the confidence interval will have a margin of error of 0.03?

27. Call me: A sociologist wants to construct a 95% confidence interval for the proportion of...

27. Call me: A sociologist wants to construct a 95% confidence interval for the proportion of children aged 8–10 living in New York who own a cell phone. a. A survey by the National Consumers League estimated the nationwide proportion to be 0.32. Using this estimate, what sample size is needed so that the confidence interval will have a margin of error of 0.02? b. Estimate the sample size needed if no estimate of p is available. c. If the...

Construct a 99% confidence interval of the population proportion using the given information. x=120, n=200 The...

Construct a 99% confidence interval of the population proportion using the given information. x=120, n=200 The lower bound is ----- The upper bound is ------ (Round to three decimal places as needed.)

A sociologist wants to construct a 90% confidence interval for the proportion of children aged 8-10...

A sociologist wants to construct a 90% confidence interval for the proportion of children aged 8-10 living in New York who own a cell phone. A survey by the National Consumers League taken in 2012 estimates the nationwide proportion to be 0.41. Using this estimate, what sample size is needed so that the confidence interval will have a margin of error of 0.02?

Subjects