Question

If xx is a binomial random variable, compute p(x)p(x) for each of the following cases:

(a)  n=5,x=5,p=0.2
p(x)=

(b)  n=3,x=1,p=0.7
p(x)=

(c)  n=4,x=2,p=0.6
p(x)=

(d)  n=3,x=0,p=0.3
p(x)=

The rates of on-time flights for commercial jets are continuously tracked by the U.S. Department of Transportation. Recently, Southwest Air had the best rate with 80 % of its flights arriving on time. A test is conducted by randomly selecting 1010 Southwest flights and observing whether they arrive on time.

(a)  Find the probability that exactly 88 flights arrive late.

(b)  Would it be unusual for Southwest to have 99 flights arrive on time?
(Enter YES or NO)    

Answer 1

=COMBIN(5,5)	1

=COMBIN(3,1)	3

=COMBIN(4,2)	6

=COMBIN(3,0)	1

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=COMBIN(10,8)	45