For versions of Excel: Excel for Office 365, Excel for Office 365 for Mac, Excel 2016, Excel 2016 for Mac, Excel 2013, Excel 2011 for Mac, Excel 2010, Excel 2008 for Mac, Excel 2007
The TDIST function allows you to test hypotheses using the p-value instead of a critical value. All you need is a calculated t-statistic, sample size, and whether you are doing a one or two-tailed test. Then you just plug and chug! TDIST returns a p-value based on these parameters. then you just compare this p-value to the test alpha to make a decision about your null hypothesis. If p is less than alpha you can reject the null. If it is not less than alpha you cannot reject the null, i.e. there is an unacceptable probability that your result is from random chance.