60% of the school population voted Alan as the president of student council. A random sample of 10 students was taken from the school population.

Calculate the probability of

a) 3 students voted Alan as the president.

Ans:

b) less than 3 students voted Alan as the president.

Ans:

c) at least 3 students voted Alan as the president.

Ans:

Question

60% of the school population voted Alan as the president of student council. A random sample of 10 students was taken from the school population.

 

 Calculate the probability of

 

a)    3 students voted Alan as the president.

Ans:  

 

b)    less than 3 students voted Alan as the president.

Ans:  

 

c)    at least 3 students voted Alan as the president.

Ans:

amriju · Answer

a)10C3*.6

amriju · Answer

b) summation( i= 0,1,2) 10Ci*.6

amriju · Answer

c)1-b

anonymous · Answer

so for (b) is it 0.01 after rounding off to 2 d.p?

anonymous · Answer

I'm not sure of the answers, sorry :(

amriju · Answer

pellet..it should be 0.6^3 for a..0.6^i for b..

anonymous · Answer

oh for a is 0.216, how about part b? :)

amriju · Answer

part b is like less than 3 students..so you can say it consists of three cases...0 students voted, 1 student voted or 2 students voted..you know how to determine the prob of each one of them...and you need to add all of them...

anonymous · Answer

can you list down the answers so I can check with mine?

amriju · Answer

ok..wait..

anonymous · Answer

I got these:
(a) 0.04 (2d.p)
(b) 0.216 (0.22 2d.p)
(c) 0.784 (0.78 2d.p)

amriju · Answer

and a) is not 0.216..i meant .6^3*10C3...not .6*10^3 as I posted earlier..i meant that

anonymous · Answer

i need all the final answers thanks :)

amriju · Answer

k..

amriju · Answer

a) .04

anonymous · Answer

yea got the same as yours for part a

amriju · Answer

b is too big... :( :(

amriju · Answer

are you doing probabilty using binomial theorem?

anonymous · Answer

binomial distribution?

anonymous · Answer

:<

amriju · Answer

yo:)

amriju · Answer

whats that smiley?

anonymous · Answer

sad one...

anonymous · Answer

How about I ask another question?

amriju · Answer

yeah...no problem...but learn binomial distribution  and you'll be able to solve problems like this

anonymous · Answer

okay I message you or...?

amriju · Answer

no probs..

anonymous · Answer

Sent you :)

amriju · Answer

yup..got it..

amriju · Answer

its not clear if he attempted all the questions..assuming he did..then..a) 15C2*(.2)^2(.8)^13

amriju · Answer

b) summation that he scored 0, 1, 2 ,3 or 4 marks..use the same process as in part a..

anonymous · Answer

oh thanks got both the questions already. help me with the last I posted :)