For those who prefer to work with Excel, here is a worksheet that may help. Enter your data into the blue cells. You may enter an “x” as well as the a and the b if you are asked for a between probability. The answers will be in the yellow cells. There is a link to download a copy of the workbook at the bottom.
I will send you a copy of the Excel workbook if you send me an email (firstname.lastname@example.org )saying you have subscribed to my YouTube channel https://www.youtube.com/c/TheStatsFilesDawnWrightPhD