Calculating the P-Value

In the box below, please enter the p-value for the null hypothesis and the data given above. Once you have done so, click on the “Check your answer!” button. Please round your answer to the ten-thousandths place.

Your guess:

You got the correct answer of 0.1475. Congratulations!

Unfortunately, your answer was not correct. Either try again or click on “Show Solution” below to see how to obtain the correct answer.

Show Formula

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Here is the formula you can use to calculate the z test statistic.

In this formula, there are a few symbols to know:

Show Solution

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Thus, the p-value for these data and this hypothesis is 0.1475. As this p-value is greater than the usual α = 0.05, we fail to reject the null hypothesis. What we observed is reasonably common if the null hypothesis is true.

Show the R Code

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The following code will perform the t-test of the above null hypothesis with the data. Copy and paste the following code into your R script window, then run it from there.

The p-value follows “p-value =” near the top of the output.

Show the Excel Code

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For some reason, there is no one-sample t-test in the base Excel program. I am sure, however, that one can purchase an add-on to perform this calculation. In lieu of spending that money, copy and paste the following code into your Excel spreadsheet window, making sure the value sample ends up in A1 after pasting.

The t test statistic is the number calculated in cell C5. Again, when you paste this code into Excel, make sure that you start the pasting in cell A1. To help with that, you may want to also copy this notice. It seems to help.