Question

two friends argue over who brushes their teeth more often. to settle the argument, they keep track of the number of mornings and nights they brush and calculate a probability. these are shown in the table. who is more likely to brush both morning and evening? assume all events are independent. a. braxton. he has a 0.72 probability of brushing both times. b. arabella. she has a 0.64 probability of brushing both times. c. braxton. he has a 0.61 probability of brushing both times. d. arabella. she has a 0.79 probability of brushing both times

Explanation:

Step1: Calculate Braxton's joint probability

For independent events, $P(\text{both}) = P(\text{morning}) \times P(\text{evening})$.
Braxton: $0.85 \times 0.72 = 0.612$ (rounded to 0.61).

Step2: Calculate Arabella's joint probability

Arabella: $0.79 \times 0.81 = 0.6399$ (rounded to 0.64).

Step3: Compare probabilities

Braxton's 0.61 < Arabella's 0.64.

Answer:

B. Arabella. She has a 0.64 probability of brushing both times.