Homework Help: statistics

Posted by Diana on Sunday, October 14, 2012 at 6:04pm.

A researcher wishes to estimate with 95% confidence the proportion of adults who have high speed internet access. Her estimate must be accurate within 4% of the true proportion.
1. Find the minimum sample size needed using a prior study that found that 48% of the respondents said they have high speed internet access
2. No preliminary estimate is available. Find the minimum sample size needed.

statistics - MathGuru, Monday, October 15, 2012 at 8:25pm
Formula to find sample size:
n = [(z-value)^2 * p * q]/E^2
... where n = sample size, z-value is found using a z-table for 95% confidence, p = .48, q = 1 - p, ^2 means squared, * means to multiply, and E = .04 (or 4%).

For 2): use p = .5 (when no value is stated in the problem), q = 1 - p

I hope this will help get you started.

Answer this Question

Related Questions

Elementary Statistics - 1) Construct a confidence interval of the population ...
Statistics - A researcher wishes to estimate, with 95% confidence, the ...
statistics - A researcher at a major hospital wishes to estimate the proportion ...
Basic Statistics - Historically, the proportion of adults over the age of 24 ...
statistics - Scores on a certain test are normally distributed with a variance ...
statistics - 2. An investigator wants to estimate caffeine consumption in high ...
statistics - Scores on a certain test are normally distributed with a variance ...
statistics - A researcher wants to estimate the proportion of a population which...
Statistics - An investigator wants to estimate caffeine consumption in high ...
Statistics - Find the minimum sample size that should be chosen to assure that ...

For Further Reading

First Name:
School Subject:
Answer: