Calculating Probabilities with Binomial Distribution

[RSS]

Hi,Can anyone help me with this one?

Probability of an event occurring is 0.6

Find,
1)Probability of 1 of such events occurring out of total 5?

2)and 4 of such event occurring out of total 5.?



Answers given are:

1) 0.768
2) 0.2592


Please help me out by giving and explaining this one?..
thnks in advance

 

[radou]

You may want to use the binomial distribution f(k)=\left( \begin{array}{c} n \\ k \end{array} \right) p^k (1-p)^{n-k}, where n is the number of trials, and k the number of times an event whose probability is 0.6 occured.

 

[RSS]

You may want to use the binomial distribution f(k)=\left( \begin{array}{c} n \\ k \end{array} \right) p^k (1-p)^{n-k}, where n is the number of trials, and k the number of times an event whose probability is 0.6 occured.

I tried..but still not getting the ans..dunno where am going wrong..could u pls solve it and show me...
thnk u very much!...i guess i am making the same mistake again n again..but can't see thro ' it..will really appreciate if u solve it and explain...

U r right tht we have to use binomial distribution..is there any other way also to solve it?

thnks

 

[CRGreathouse]

Complete words, please!

I tried..but still not getting the ans..dunno where am going wrong..could u pls solve it and show me...
thnk u very much!...i guess i am making the same mistake again n again..but can't see thro ' it..will really appreciate if u solve it and explain...

U r right tht we have to use binomial distribution..is there any other way also to solve it?

I'm not sure at all where you're going wrong. You have the formula -- just plug in the appropriate values and you have the answer. What are you getting, and how?

 

[HallsofIvy]

You have already been told to use
f(k)=\left( \begin{array}{c} n \\ k \end{array} \right) p^k (1-p)^{n-k}

When p= 0.6, n= 5, P(1)= \frac{5!}{(4!)(1!)}.6^1 .4^4
= 5(.6)(0.025)= 0.0768. Was it the arithmetic you had trouble with?

To answer (2) take k= 4 rather than 1.

 

[RSS]

sorry frnds..was making a very silly mistake with decimals..I got it after radou's 1st reply..was just trying to work out if there is any other way to solve besides using the binomial formula..
anyways, i have stuck with wht u all suggest..thnks again all of you!..appreciate it!