Answer:
And we can use the probability mass function and we got:
Then the probability that all three have a smart phone is 0.091
Step-by-step explanation:
Let X the random variable of interest "number of students with smartphone", on this case we now that:
The probability mass function for the Binomial distribution is given as:
Where (nCx) means combinatory and it's given by this formula:
And we want to find this probability:
And we can use the probability mass function and we got:
Then the probability that all three have a smart phone is 0.091