MATH1015 Assignment 1 (1 Viewer)

[bonamy]

The distribution for scores of a particular IQ test for adults is approximately normal
with mean 100 and standard deviation 15. Show that for a randomly selected adult, the probability of IQ less than 106 is 0.6554. For 12 randomly selected adults, what is the probability that at least 5 will have IQ's less than 106?

I'm having trouble with the part in bold. Any help would be appreciated.
Thanks

 

[velox]

You should use the normal approximation formula for the first bit and use binomial for the second bit. It should be a piece of cake from there.

Remember, at least 5 people having IQ's less than 106 is the same as having at most 7 with IQ's above 106. Use the second statement in the binomial formula.

Let me know if you have any further problems as im tutoring someone who has the same assignment