## Minimum Sample Size Calculator for Population Proportion Confidence Interval

If you are conducting a survey, you will need to decide on the number of people you need to sample. That, of course, depends upon how confident you want to be and how accurately you want to predict the population proportion based on your survey results. If you want to be 95% confident, that is […]

## 7.4.5 Single Sample Hypothesis Test for a Proportion

Here is the screenshot of the basic StatCrunch solution. [My Excel calculator for running this test is found here.] As always for proportion problems, we have to check first to be sure np and nq or n*(1-p) are both > 5. If they are, we can use the normal approximation to the binomial (a proportion […]

## Single-sample Hypothesis Test for a Proportion

Consider the following problem statement: An article in an online magazine states that 40% of home buyers found their real estate agent through referrals by a friend. However, a professor in a local college sampled 1000 home buyers and found that 426 chose an agent recommended by a friend. Does the data refute the claim […]

## No Standard Deviation? How do I get the standardized test statistic?

I get this question a lot in my BUS 233 Business Statistics course. It comes when students see a problem similar to the following in their homework or on a quiz: In a sample of 1000 home buyers, you find that 457 home buyers found their real estate agent through a friend. At α=0.08, can […]