If your field {Decimal} is a numeric rather than text field you should put 0.75 not "0.75" etc.

Is your {Decimal} field type a number, formula, or text? In addition to following John’s advice about using a number in your switch, if your field is a formula, the formula results might not be exact values to match your switch. You might need to do some rounding in your formula or you might want to consider nested IFs. 

My {Decimal} field is indeed a number and, therefore, removing the quotation marks worked like a charm. Thanks, John_B2, for the solution. And thanks, kuovonne, for sharing suggestions in case the field wasn't a number. I really appreciate the help! 🙂