WorksheetsStatistics End of Week 15 assessment.
Total questions: 20
Worksheet time: 13mins
Suppose 2% of all credit card transactions are fraudulent. If there 50 transactions per day, what is the probability that at least 2 transactions are fraudulent.
Uniform
Binomial
Geometric
Hypergeometric
Suppose we randomly select 5 cards without replacement from an ordinary deck of playing cards. We are interested in the probability of getting exactly 2 red cards (i.e., hearts or diamonds)
What type of probability distribution is represented?
Binomial distribution.
Geometric distribution.
Hypergeometric distribution.
None of the above mentioned.
The owners of a large pet store have determined that 65% of their customers own dogs. They select 15 customers at random to survey. Let D be the number of customers they survey who have dogs.
What type of variable is D?
Binomial distribution.
Geometric distribution.
Hypergeometric distribution.
None of the above mentioned.
The probability that a student is accepted to a prestigious college is 0.3. If 5 students from the same school apply, We are interested in the probability that at most 2 are accepted?
What type of probability distribution is represented?
Binomial distribution.
Geometric distribution.
Hypergeometric distribution.
None of the above mentioned.
Suppose we select 5 cards from an ordinary deck of playing cards. We are interested in the probability of obtaining 2 or fewer hearts.
What type of probability distribution is represented?
Binomial distribution.
Geometric distribution.
Hypergeometric distribution.
None of the above mentioned.
A deck of cards contains 20 cards: 6 red cards and 14 black cards. 5 cards are drawn randomly without replacement. We are interested in the probability that exactly 4 red cards are drawn.
What type of probability distribution is represented?
Binomial distribution.
Geometric distribution.
Hypergeometric distribution.
None of the above mentioned.
The probability of a defective steel rod is 0.01. Steel rods are selected at random. We are interested in the probability that the first defect occurs on the ninth steel rod.
What type of probability distribution is represented?
Binomial distribution.
Geometric distribution.
Hypergeometric distribution.
None of the above mentioned.
Suppose that you are looking for a student at your college who lives within five miles of you. You know that 55% of the 25,000 students do live within five miles of you. You randomly contact students from the college until one says he or she lives within five miles of you. You are interested in the probability that you need to contact four people
What type of probability distribution is represented?
Binomial distribution.
Geometric distribution.
Hypergeometric distribution.
None of the above mentioned.
The lifetime risk of developing pancreatic cancer is about one in 78 (1.28%). Suppose we randomly sample 200 people. Let X = the number of people who will develop pancreatic cancer. What kind of distribution is X?
Binomial distribution.
Geometric distribution.
Hypergeometric distribution.
None of the above mentioned.
A shop sells large birthday cakes at a rate of 2 every 3 days.
Find the probability of selling no large birthday cakes on a randomly selected day.
Give your answer to 4 decimal places.
(a)
On a typical summer's day, a boat company hires rowing boats at a rate of 9 per hour,
Find the probability of hiring out at least 6 boats in a randomly selected 30-minute period.
Give your answer to 4 decimal places.
(a)
The mean number of faults in a new house is 8. What is the probability of buying a new house with exactly 1 fault?
Give your answer to 4 decimal places.
(a)
A computer crashes once every 2 days on average. What is the probability of there being 2 crashes in one week?
Give your answer to 4 decimal places.
(a)
A typist makes on average 2 mistakes per page. What is the probability of a particular page having no errors on it?
Give your answer to 4 decimal places.
(a)
In the manufacture of car tyres, a particular production process is know to yield 10 tyres with defective walls in every batch of 100 tyres produced. From a production batch of 100 tyres, a sample of 4 is selected for testing to destruction. Find the probability that the sample contains 1 defective tyre.
(note, this is a hypergeometric distribution)
0.2996
0.6516
0.9512
0.0488
0.3484
A batch of 10 rocker cover gaskets contains 4 defective gaskets. If we draw samples of size 3 without replacement, from the batch of 10, find the probability that a sample contains 2 defective gaskets.
(a)
At a certain restaurant, there is a 70% probability that the flowers on your table will be yellow. If you are there with a group that is occupying 6 tables, what is the probability that 5 of the tables will have yellow flowers?
70%
70.6 %
30.5 %
5.0 %
A committee of 10 people is to be chosen from 20 senior students and 40 Junior Students. Determine the expected number of senior students on the committee.
2
5
3.3
4.4
Suppose that a technology task force is being formed to study technology awareness among instructors. Assume that
ten people will be randomly chosen to be on the committee from a group of 28 volunteers, 20 who are technically proficient
and eight who are not. We are interested in the number on the committee who are not technically proficient.
Find the probability that at most three on the committee are not technically proficient.
(give your answer to 4 decimal places)
(a)
