Math
posted by Zhanise .
Trudi Can Either Walk TO School, Or She Can Take The Bus. The Probability Of Her Taking The Bus On Any Given Day Is 0.77.
Assuming That Her Choice Of Transport On Any Given Day Is Independent Of Her Choice Of Transport On Another Day, Find Out The Probability Of Her Taking The Bus To School On Exactly 3 Days, Out Of A Total Of 5 Days.

p=P(B)=0.77
q=1P(B)=0.23 = probability of walking
n=5 (days)
r=3 days taking bus
Given independence of choice from day to day, and probability does not vary, then we can use the binomial distribution.
To calculate the probability of taking the bus exactly r days out of n:
P(n,r,p)=nCr*p^r*(1p)^(nr)
For 3 days out of 5,
probability = P(5,3,0.77)
which turns out to be about a quarter.
Respond to this Question
Similar Questions

Geometry
I'm really stuck with this question can someone please help me. A bus is scheduled to stop at a certain bus stop every 45 minutes. At the end of the day, buses still stop after every 45 minutes, but because delays often occur earlier … 
MTH 156
"Emergency Please Help"!!!!! A bus is scheduled to stop at a certain bus stop every 45 minutes. At the end of the day, buses still stop after every 45 minutes, but because delays often occur earlier in the day, the bus is never early … 
probability
A survey of 850 students conducted in two schools showed the following results: School A: *Students who took the bus = 400 * Students who did not take the bus = 150 Total = 550 School B: *Students who took the bus = 200 * Students … 
English
Can you please check these sentences please? 
Montgomery
There are 315 students in sixth grade and about 8/15 take the bus to school each day. Estimate the number of students that ride the bus each day. 
math
In jims,5 times as many students take the bus as those who walk. A total of 24 students walk or take the bus. How many more students take the bus than walk to school? 
Math
You live 2 3/4 miles from school. In the morning, you walk 1/3 mile directly toward school to the bus stop. Later, when you get off the bus, you walk home the same distance. How many miles do you ride to and from school each day? 
English
1. She took the bus to school every day. 2. She rode the bus to school every day. 3. She get on the bus to school every day. (Are they all possible? 
math
a bus ride costs $1.50. A 30day bus pass costs $36. Write an equation to represent the number of bus rides you would need to take for the bus pass to a better deal. 
Mathematics
You live 2 3/4 miles from school. In the morning, you walk 1/3 mile directly toward school to take the bus. After school, you walk home the same distance when the bus drops you off. How many miles do you ride the bus to and from school …