In: Statistics and Probability
A box of 99 cellphones contains three yellow cellphones and six green cellphones. Complete parts (a) through (d) below.
a. If two cellphones are randomly selected from the box without replacement, what is the probability that both cellphones selected will be green?
b. If two cellphones are randomly selected from the box without replacement, what is the probability there will be one green cellphone and one yellow cellphone selected?
c. If three cellphones are selected with replacement (the first cellphone is returned to the box after it is selected), what is the probability that all three will be yellow?
d. If you were sampling with replacement (the first cellphone is returned to the box after it is selected), what would be the answers to (a) and (b)?
Number of yellow cell phones = 3
Number of green cell phones = 6
Total number of cell phones = 99
(a)
In case of selection without replacement,
Number of possible selections for selecting two cell phones
Number of possible selections for selecting two green cell phones
Required probability = 0.003092146
(b)
In case of selection without replacement,
Number of possible selections for selecting two cell phones
Number of possible selections for selecting one green cell phone and one yellow cell phone
Required probability = 0.003710575
(c)
In case of selection with replacement,
Number of possible selections for selecting three cell phones
Number of possible selections for selecting three yellow cell phones
Required probability = 0.00002782647
(d)
In case of selection with replacement,
For problem in (a)
Number of possible selections for selecting two cell phones
Number of possible selections for selecting two green cell phones
Required probability = 0.003673095
For problem in (b)
Number of possible selections for selecting two cell phones
Number of possible selections for selecting one green cell phone and one yellow cell phone
Required probability = 0.001836547