5.2 Notes (Cont.)

Binomial Probabilities

Calculator Tips

TI 83 Calculator Tips

Under Dist select binompdf to perform a single binomial calculation. Once you have selected this choice you should see on your screen binompdf(

Following the open parenthesis you need to provide n, p, and r separated by commas so that the screen now reads binompdf(n,p,r) where n, p, and r are the corresponding values from the problem.

Let’s reexamine

Ex. 2 59% of internet users are concerned about email privacy. From a random sample of 10 users, find the probability that exactly 6 of them will be concerned.

binompdf(___,____,___)

What if we wanted to know the probability that between 0 and 2 inclusively were concerned.

P(0) =P(1) =P(2) =

However we have another option, binomcdf finds the sum of the probabilities for 0 through r successes out of n trials,

P(0-r) = binomcdf(n,p,r)

so for P(0-2)

we could have entered

binomcdf(___,____,___)

+

What if we want to know the probability of at least 6?

P(0-10) = 1

P(0-5) + P(6-10) = 1

P(6-10) = 1 – P(0-5)

Therefore, P(6-10) = 1 – P(____) = 1 – binomcdf(___,_____,___)

Ex. 3 The seeds of a given hybrid of plant have a 70% chance of germinating.

a) What is the probability of exactly 8 seeds germinating out of 10 seeds planted?

b) What is the probability of at most 3 seeds germinating out of 10 seeds planted?

c) What is the probability of at least 8 seeds germinating out of 10 seeds planted?

d) What is the probability of at least 8 seeds not germinating out of 10 seeds planted?

Assignmentp. 192 #10 (c – don’t compare or use table), 11, 12, 13, 15, 16 a-c