Final answer:
The question about the number of cakes sold cannot be answered without additional data on the probability distribution or sales record. We do not have the necessary information to calculate or estimate the number of cakes sold.
Step-by-step explanation:
The provided information lacks specific data on the number of cakes sold. To answer a question such as 'How many cakes did they sell?', we would need the probability distribution or sales record from the baker. Without such data, we cannot conclusively determine the number of cakes sold from the options (a) 5, (b) 6, (c) 7, or (d) 8.
In case this is a hypothetical scenario tied to the probability distribution information mentioned in the instructions, the expected value or mean of the distribution would help us estimate on average how many cakes are sold. However, since such critical numerical details are missing, we can't calculate the expected value.
It's also possible that this question might relate to an exercise or a scenario described in a textbook or another educational resource, which has not been provided.