Answer:
-13/23 is the probability a customer on plan B will text
Explanation:
Assuming the categorization is mutually exclusive, (customers either text or internet, but none of them both) the final number for Plan B customers in the sample is the sum of the ones in each section.
plan B customer are 13+10=23
The problem tells you that 23 plan B customers do text.
Because 13 out of 23 customers surveyed use the phone for text, the probability that a plan B customer will use the phone for texting is 13/23
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