WorksheetsStatistic and Probability II
Total questions: 81
Worksheet time: 1hrs 1mins
Consider the following table with information about all of the students taking Statistics at Happy High School.
Find P( Full-time | Male)
7/3
3/10
3/7
4/7
Consider the following table with information about all of the students taking Statistics at Happy High School.
Find P( Female | Part-time) =
15/31
43/71
31/43
15/43
A new credit card has been issued to 2000 customers. Of these customers, 1500 hold a Visa, 500 hold an AA card, and 40 hold a Visa and AA card. Find the probability that a random chosen customer holds an AA, given they hold a Visa.
.0267
37.5
.02
.3333
A science teacher gave her class two tests. 25% of the class passed both tests and 42% of the class passed the first test. What percent of those who passed the first test also passed the second?
59.5%
10.5%
1.6%
Not enough information
A jar contains black and white marbles. Two marbles are chosen without replacement. The probability of selecting a black marble and then a white marble is 0.34, and the probability of selecting a black marble on the first draw is 0.47. What is the probability of selecting a white marble on the second draw, given that the first marble drawn was black?
16%
1.38%
72.3%
Not enough information
45% total of the children in a school have a dog, 30% total have a cat, and 18% have a dog and cat. What percent of those who have a cat also have a dog?
60%
40%
24%
1.7%
Tom will randomly select from a treat bag containing 6 lollipops and 4 gum balls. Tome will select a treat, replace it, and then select a second treat.
Independent
Dependent
Sue will randomly select from a treat bag containing 6 lollipops and 4 gum balls. Sue will select a treat, not replace it, and then select a second treat.
Independent
Dependent
What is the probability when Tom will randomly select from a treat bag containing 6 lollipops and 4 gum balls. Tom will select a 1 lollipop, replace it, and then select a 1 gum ball.
1/24
1/90
6/25
1/10
What is the probability when Sue will randomly select from a treat bag containing 6 lollipops and 4 gum balls. Sue will select a treat, not replace it, and then select a second treat. Sue will select a gum ball then a lollipop.
1/24
4/15
1/100
2/10
Two fair coins are flipped at the same time. What is the probability that both with display heads?
1/2
1/4
2%
1%
Two fair coins are flipped at the same time. What is the probability that both with display heads?
Independent
Dependent
A box contains 9 new light bulbs and 6 used light bulbs. Each light bulb is the same size and shape. Meredith will randomly select 2 light bulbs from the box without replacement. What is the probability Meredith will select a new light bulb and then a used light bulb?
1/54
2/15
6/25
9/35
You are at the movies with your friends and decided to buy a small bag of gummy bears. There are 4 red bears, 5 green bears, and 3 yellow bears in the bag. What is the probability that you will get yellow gummy bears and then red gummy bears?
The probability is 3/11
The probability is 1/11
The probability is 3/132
The probability is 3/12
A spinner consists of two A’s, three B’s, and three C’s. What is the probability of spinning a B and then an A?
2/8
3/28
3/32
1/4
A box contains 3 black pens, 7 blue pens, and 5 red pens. Without looking, P(red and black)
1/14
1/15
2/15
3/15
If a person selected at random from this population tests positive for the virus, what is the probability that this person is actually infected? [Round to the nearest percent.]
If 8% of cars in the city are black, what is the probability that a black car really was involved in the accident?
You see a dragonfly in this habitat with an extra pair of wings. What is the probability that it is a member of the rare species?
Suppose that 20 equally-qualified applicants apply for jobs at a company in this industry, and six are from Iowa. If this company hires four people from this set of applicants, but none are from Iowa, what is the probability that this company discriminates?
You see a flight from this airline arriving on time. What is the probability that it departed on time?
I hand you one of these urns at random and you select a ball from that urn at random.
If that ball is white, what is the probability that I handed you Urn A? [Round to the nearest percent.]
If a person selected at random from this population tests positive for the virus, what is the probability that this person is actually infected? [Round to the nearest percent.]
What is the formula for conditional probability?
P(A|B) = P(A) / P(B)
P(A|B) = P(A) - P(B)
P(A|B) = P(A) * P(B)
P(A|B) = P(A ∩ B) / P(B)
In a deck of 52 cards, what is the probability of drawing a king given that the card drawn is a face card?
1/4
1/2
1/3
1/5
Explain Bayes' theorem and provide an example of its application.
Bayes' theorem is used in medical diagnosis, such as in the case of a patient testing positive for a disease and the calculation of the actual probability of having the disease given the test result and the prevalence of the disease in the population.
Bayes' theorem is used in cooking recipes, such as calculating the probability of a dish turning out well based on the ingredients used
Bayes' theorem is used in weather forecasting, such as predicting the chance of rain based on historical data
Bayes' theorem is used in sports betting, such as determining the likelihood of a team winning based on their previous performance
A bag contains 3 red balls and 2 green balls. If a ball is drawn at random, what is the probability that it is red given that it is not green?
1/5
3/5
4/5
2/5
What is the difference between marginal probability and conditional probability?
Marginal probability is the probability of an event occurring given that another event has already occurred, while conditional probability is the probability of an event occurring without any condition.
Marginal probability is the probability of an event occurring given that another event has already occurred, while conditional probability is the probability of an event occurring given that another event has already occurred.
Marginal probability is the probability of an event occurring without any condition, while conditional probability is the probability of an event occurring without any condition.
Marginal probability is the probability of an event occurring without any condition, while conditional probability is the probability of an event occurring given that another event has already occurred.
In a survey, 60% of people like chocolate ice cream, 40% like vanilla ice cream, and 30% like both. What is the probability that a person chosen at random likes chocolate or vanilla ice cream?
20%
80%
50%
70%
If P(A) = 0.4, P(B) = 0.3, and P(A|B) = 0.5, what is P(B|A)?
0.8
0.2
0.375
0.6
A factory produces 3 types of products: A, B, and C. The probability of a product being defective is 0.1, 0.15, and 0.2 for A, B, and C respectively. If a defective product is found, what is the probability that it is type B?
0.05
0.3
0.18
0.2143
What is the general formula for Bayes' theorem?
P(A|B) = (P(B|A) * P(A)) / P(B)
P(A|B) = (P(A) + P(B)) / P(B)
P(A|B) = (P(A) * P(B)) / (P(A) + P(B))
P(A|B) = (P(A) * P(B)) / P(B|A)
In a class, 60% of students are girls and 40% are boys. If 70% of the girls and 80% of the boys passed the exam, what is the probability that a student who passed the exam is a girl?
0.6
0.4
0.7
0.8
A probability law used to compute the probability of the union of two events. It is P(a ∙ B) = P(a) + P(B) − P(a ∩ B). For mutually exclusive events, P(a ∩ B) = 0; in this case the addition law reduces to P(a ∙ B) = P(a) + P(B).
Addition Law
Bayes Theorem
Classical Method
Conditional Probability
Two requirements that restrict the man- ner in which probability assignments can be made: (1) for each experimental outcome Ei we must have 0 ≤ P(Ei) ≤ 1; (2) considering all experimental outcomes, we must have P(E1) + P(E2) + . . . + P(En) = 1.0.
Multiplication Law
Combination
Basic requirements for assigning probabilities
Mutually Exclusive Events
A method used to compute posterior probabilities.
Joint Probability
Bayes’ theorem
marginal Probability
Multiplication Law
A method of assigning probabilities that is appropriate when all the experimental outcomes are equally likely.
Independent Events
Combination
Multi-step Experiment
Classical method
In an experiment we may be interested in determining the number of ways n objects may be selected from among n objects without regard to the order in which the n objects are selected.
Complement of A
Conditional Probability
Combination
Intersection of A & B
The event consisting of all sample points that are not in a.
Complement of A
Event
Independent Events
Intersection of A & B
The probability of an event given that another event already occurred. The conditional probability of a given B is P(a ∣ B) = P(a ∩ B)/P(B
Conditional probability
Marginal probability
Joint probability
Multiplication law
A collection of sample points.
Experiment
Independent events
Event
Mutually exclusive events
A process that generates well-defined outcomes.
Combination
Complement of A
Event
Experiment
Two events a and B where P(a ∣ B) = P(a) or P(B ∣ a) = P(B); that is, the events have no influence on each other.
Multiple-step experiment
Independent events
Event
Experiment
The event containing the sample points belonging to both a and B. The intersection is denoted a ∩ B.
Event
Joint probability
intersection of A and B
Experiment
The probability of two events both occurring; that is, the probability of the intersection of two events.
Conditional probability
Multiplication law
Marginal probability
Joint Probability
The values in the margins of a joint probability table that provide the probabilities of each event separately.
Marginal Probability
Joint Probability
Conditional Probability
Classical Method
An experiment that can be described as a sequence of steps.
Experiment
Event
Multi-step Experiment
Marginal Probability
A probability law used to compute the probability of the intersection of two events. It is P(a ∩ B) = P(B)P(a ∣ B) or P(a ∩ B) = P(a)P(B ∣ a). For independent events it reduces to P(a ∩ B) = P(a)P(B).
Baye's Theorem
Multiplication Law
Joint Probability
Marginal Probability
Events that have no sample points in common; that is, a ∩ B is empty and P(a ∩ B) = 0.
Mutually exclusive events
Independent events
Event
Experiment
In an experiment we may be interested in determining the number of ways n objects may be selected from among n objects when the order in which the n objects are selected is important.
Probability
Sample Point
Permutation
Prior Probabilities
Revised probabilities of events based on additional information.
Subjective method
Prior probabilities
Probability
Posterior probabilities
Initial estimates of the probabilities of events.
Posterior probabilities
Probability
Prior probabilities
Relative frequency method
A numerical measure of the likelihood that an event will occur.
A method of assigning probabilities that is appropriate when data are available to estimate the proportion of the time the experimental outcome will occur if the experiment is repeated a large number of times.
Relative Frequency Method
An element of the sample space. A sample point represents an experimental outcome.
The set of all experimental outcomes
A method of assigning probabilities on the basis of judgment.
unreliable method
objective method
random method
subjective method
A graphical representation that helps in visualizing a multiple-step experiment
tree diagram
The event containing all sample points belonging to a or B or both. The union is denoted a ∙ B.
Union of A & B
Event
Experiment
Joint Probability
A graphical representation for showing symbolically the sample space and operations involving events in which the sample space is represented by a rectangle and events are represented as circles within the sample space.
A composite price index based on the prices of a group of items.
A monthly price index that uses the price changes in a market basket of consumer goods and services to measure the changes in consumer prices over time.
Aggregate price indexes designed to show price trends and movements associated with common stocks
Dow Jones averages
A quantity index designed to measure changes in the physi- cal volume or production levels of industrial goods over time.
A weighted aggregate price index in which the weight for each item is its base-period quantity.
A weighted aggregate price index in which the weight for each item is its current-period quantity
Paasche index
A price index for a given item that is computed by dividing a current unit price by a base-period unit price and multiplying the result by 100
A monthly price index designed to measure changes in prices of goods sold in primary markets (i.e., first purchase of a commodity in nonretail markets).
An index designed to measure changes in quantities over time
Quantity Index
A composite price index in which the prices of the items in the composite are weighted by their relative importance.
weighted aggregate price index
