Question isn't complete but we make assumptions in order to complete the question and explain
Answer and explanation:
If we are given a table on calories burned by Robyn on weekdays from Monday to Friday and on this table Robyn burnt 500 calories on Monday and burnt 400 calories on Wednesday, then we are required to determine the ratio of calories burnt on Wednesday to calories burnt on Monday:
Calories burnt on Wednesday = 400
Calories burnt on Monday =500
Ratio of calories burnt on Wednesday to calories burnt on Monday =400/500=4/5
Ratio =4:5