The sum of the probabilities of choosing each weekday is:
0.12 + 0.07 + 0.05 + 0.28 + 0.15 + p(Friday) + p(Weekend) = 1
where p(Friday) is the probability of choosing Friday and p(Weekend) is the probability of choosing one of the weekend days (Saturday or Sunday).
We know that the probability of choosing one of the weekdays is:
p(Weekdays) = 0.12 + 0.07 + 0.05 + 0.28 = 0.52
So, the probability of not choosing one of the weekdays is:
p(Not Weekdays) = 1 - p(Weekdays) = 1 - 0.52 = 0.48
Therefore, the probability that it will not choose one of the weekdays is 0.48.