Answer:
Days : Monday Tuesday Wednesday Thursday
Probability: 0.25 0.15 0.25 0.35
Explanation:
The number of apples sold :
Monday = 20
Tuesday = 12
Wednesday = 20
Thursday = 28
Total number of apples sold in 4 days = 20 + 12 + 20 + 28 = 80
Formula for probability:

Probability of each day
Monday =

Tuesday =

Wednesday =

Thursday =

Therefore the probability distribution table for this situation is
Days : Monday Tuesday Wednesday Thursday
Probability: 0.25 0.15 0.25 0.35