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Statistics help!!!!!!!!! Watch

    • Thread Starter

    Hi everyone I am currently in year 12 and have just started S1. I am findind it ok and I thought I had it figured out. But when I was doing some past paper questions on Standard deviation when I noticed that the calculator was giving different answers to when I put the numbers into the formula. Has anyone experienced this and if yes can you explain why this is?

    The formula that I used is this:

    Your calculator may well be using the s.d. formula for a population, not a sample, which is the same except there is an "n" where your formula has an "n-1". Try this first to see if this is what is happening.

    From my experience with AQA S1, it doesn't matter which version you use in the questions that are about straightforward averages and measures of spread. In questions about estimation and confidence intervals, you need to use the right one!
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