Question

Tamara wants to know how likely her bus is to be late.
She records the data over a month and finds it was late on
7 out of 25 times that she went to catch it.
Estimate the probability of the bus being late on any given day.

Answer 1

Related Question

The probability that Meena is on time to catch the bus to her office is 0.8. Find the probability that she is late

(a) exactly twice in a 6-day week, and (b) at least once in a 6-day week.

Solution

P(Meena on time):0.8

P(Meena is late):1−0.8=0.2

i) probability that she is late exactly twice: (62)(0.8)2(0.2)4

ii) probability that she is late at least once: (61)(0.8)5(0.2)1+(62)(0.8)4(0.2)2+(63)(0.8)3(0.2)3+(64)(0.8)2(0.2)4+(65)(0.8)1(0.2)5+(66)(0.8)0(0.2)6

⇒6(0.32768)(0.2)+15(0.4096)(0.4)+20(0.512)(0.8)+15(0.64)(0.16)+6(0.8)(0.32)+(0.000064)

⇒3.93+2.46+8.19+1.536+0.000064

⇒16.116064