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Exercise

Sample Size III

You're interested in looking at how many days in the week students drink alcohol, and need to know what kind of sample size to use. You know that to find this out, you need a Z-score, a margin of error and a standard deviation. In the last exercise you established an estimated mean of 3.5, and standard deviation of 1.25. You want to calculate a confidence interval of 95%, with a margin of error of 0.2. Let's input these values into our equation to estimate our required sample size!

Remember, our formula for sample size is the population standard deviation squared, multiplied by the Z-score squared, divided by the margin of error squared. You know what Z-score to use for 95% confidence by know, don't you?

Instructions

100 XP
  • In your script, calculate the separate components of the sample size equation and assign to stated objects
  • In your script, use the separate components to calculate sample size (see formula above)
  • Remember to format your calculations correctly and use () where appropriate