Question

A certain tribe is distinguished by the fact that 45% of the males have 6 toes on their right foot.Determine using suitable approximation that the probability that in a group of 200 males from the tribe, more than 97 have six toes on their right foot.

Answer 1

lol

Answer 2

there is no standard deviation given

Answer 3

that is the question...:S

Answer 4

this is a binomial problem , either you have 6 toes (success) or you do not

Answer 5

i think you use binomial but im not sure how to do it

Answer 6

you can approximate the binomial using a normal distribution

Answer 7

like?

Answer 8

one moment

Answer 9

http://en.allexperts.com/q/Advanced-Math-1363/2009/6/Standard-normal-variable.htm

Answer 10

you can also do this with calculators

Answer 11

makes sense?

Answer 12

so i still use the x- mean / standard deviation?

Answer 13

yes

Answer 14

i get the first part and i got the n and the probability but im not sure how to continue. could you please show me the working if you get it?

Answer 15

ok

Answer 16

which part did you get

Answer 17

actually my answer is very close but not quite. i did 97.7-90/ 7.03

Answer 18

sorry 97.5-90/7.03

Answer 19

mean = n*p
std = sqrt( n*p*(1-p))

Answer 20

hm i think i got the answer actually. i didnt do it by calculator so it won't be accurate.

Answer 21

so if its more than 97 it should be 97.5?

Answer 22

we want greater than 97, so we use P( x>= 97.5)

Answer 23

so 97 to 97.5?

Answer 24

yes, because the binomial is a rectangle , but we want smooth

Answer 25

okay thank you so much for your help..:)