Please have a look this link Fitting a Gaussian (normal distribution) curve to a histogram in Tableau - The Information Lab this will help you. If possible try to share your sample workbook.
Thanks for the link Tharashasank. I have attached my workbook but don't know if it will work or not. I will try the suggestions in the link that you attached but need to figure out how I can create the bins to make it work correctly. I am not sure how to go about making my values and number of records into bins.
PET Bottle Weights.twbx 26.9 KB