Question 996845: Assume that x is a binomial experiment with n = 15 and p = 0.3.
Compute P(x = 2). Show your work.
Use Excel to get the printout of the probability distribution. Use =binom.dist function. See page 66 of the course packet and pages 155-156 of your textbook.
Use the binomial probability distribution from part c to calculate P(x ≥ 8).
Use the short-cut formula to compute E(x), and the variance and the standard deviation of x.
Found 2 solutions by Boreal, jim_thompson5910:
Answer by Boreal(15235)   (Show Source):
You can put this solution on YOUR website! P(x=2)=15C2(0.3)^2(0.7)^13=105*(0.09)(0.009688)
without rounding until the end, that is 0.0916
========
P (x>=8) Use the table. The cumulative probability through x=7 is 0.95, so the probability of >=8 is 0.05.
===============
E(x)=np=15*0.3=4.5
variance is np(1-p)=15(0.3)(0.7)=3.15
sd=1.77
Answer by jim_thompson5910(35256)  (Show Source):
You can put this solution on YOUR website! Compute P(x = 2). Show your work.
The basic template of the BINOMDIST function in excel is
BINOMDIST( Number_s , Trials, Probability_s, Cumulative )
where
Number_s = number of successes
Trials = number of trials
Probability_s = probability of success for single trial
Cumulative = boolean value (true or false) answering the question "is this cumulative?"
In this case,
Number_s = 2 (since x = 2)
Trials = 15 (n = 15)
Probability_s = 0.3 (because p = 0.3)
Cumulative = 0 (zero for false, we're not going to use cumuative here)
So to compute P(x = 2), you'll type in
=BINOMDIST(2,15,0.3,0)
Don't forget the equal sign in front.
|
|
|
