Homework SourseIn a random sample of 100 college students 60 were females
In a random sample of 100 college students, 60 were females , 65 were under 21 years of age , and 15 makes were 21 years of age or older . A student is selected at random from this sample.
What is the probability that a female student of age 21 or older is selected ?
A. 0.20
B. 0.21
C. 0.75
D. 0.95
(I chose A after doing the math, but not sure :/)
In a random sample of 100 college students, 60 were females , 65 were under 21 years of age , and 15 makes were 21 years of age or older . A student is selected at random from this sample.
What is the probability that a female student of age 21 or older is selected ?
A. 0.20
B. 0.21
C. 0.75
D. 0.95
(I chose A after doing the math, but not sure :/)
In a random sample of 100 college students, 60 were females , 65 were under 21 years of age , and 15 makes were 21 years of age or older . A student is selected at random from this sample.
What is the probability that a female student of age 21 or older is selected ?
A. 0.20
B. 0.21
C. 0.75
D. 0.95
(I chose A after doing the math, but not sure :/)
Solution
If 60 were females, then 40 are males.
If 65 were under 21, then 35 are over 21.
If 15 males are over 21, and (35 - 15) = 20 females are over 21.
Thus, the probability is
P(female and older than 21) = 20/100 = 0.20 [OPTION A, ANSWER]
