1. Nine students ask to visit a college admissions counselor. Each scheduled visit includes one student. In how many ways can they be scheduled?
2. A store received an order of 50 shirts. 20 of the shirts are blue. If one shirt is chosen out of the 50 at random, what is the probability the shirt will not be blue? Give answer as a percent.
3. Classify the event as dependent or independent.
You select a number 1 through 6 by tossing a standard number cube. You select a second number by tossing the number cube again.
4. Sam rolled a standard number cube 20 times. He rolled a five 6 times. What is the experimental probability of rolling a 5 based on Sam’s experiment? Give answer as a simplified fraction.
5. Jill is in Math Club. There are 20 students in the club. The sponsor will pick two students at random to run the meeting. What is the Probability that Jill will not be picked? Give answer as a decimal.
Thank you.
Please help me with some probability algebra questions?
2018-04-10 9:23 pm
回答 (2)
2018-04-10 9:33 pm
1.
No. of ways
= P(9, 9)
= 9!
= 362880
2.
P(The shirt will not be blue)
= 1 - P(The shirt will be blue)
= 1 - (20/50)
= 30/50
=60%
3.
Independent
The number in the second toss does not depend on the number in the first toss.
4.
Experimental probability of rolling a "5"
= 6/20
= 3/10
5.
P(Jill will not be picked)
= (No. of ways of picking 2 students from 19 students other than Jill) / (No. of ways of picking 2 students from 20 students)
= C(19, 2) / C(20, 2)
= (19!/17!2!) / (20!/18!2!)
= 19!18! / 17!20!
= 18/20
= 0.9
No. of ways
= P(9, 9)
= 9!
= 362880
2.
P(The shirt will not be blue)
= 1 - P(The shirt will be blue)
= 1 - (20/50)
= 30/50
=60%
3.
Independent
The number in the second toss does not depend on the number in the first toss.
4.
Experimental probability of rolling a "5"
= 6/20
= 3/10
5.
P(Jill will not be picked)
= (No. of ways of picking 2 students from 19 students other than Jill) / (No. of ways of picking 2 students from 20 students)
= C(19, 2) / C(20, 2)
= (19!/17!2!) / (20!/18!2!)
= 19!18! / 17!20!
= 18/20
= 0.9
2018-04-10 9:23 pm
...
2018-04-10 9:31 pm
1.
9! = 362,880 ways
2.
P(blue shirt) = 20/50
P(not a blue shirt) = 1- 20/50
= 1-2/5
= 3/5
= (3/5)(100) = 60 percent
3.
Independent
Second toss has no bearing on the first toss.
4.
P(rolling a 5) = 6/20 = 3/10
5.
P(no Jill, No Jill) = (19/20)(18/19) = 18/20 = 9/10 = 0.9
9! = 362,880 ways
2.
P(blue shirt) = 20/50
P(not a blue shirt) = 1- 20/50
= 1-2/5
= 3/5
= (3/5)(100) = 60 percent
3.
Independent
Second toss has no bearing on the first toss.
4.
P(rolling a 5) = 6/20 = 3/10
5.
P(no Jill, No Jill) = (19/20)(18/19) = 18/20 = 9/10 = 0.9
收錄日期: 2021-04-24 01:05:38
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20180410132312AASjur0