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WorksheetsSummative Test No. 2 Q3
Total questions: 15
Worksheet time: 39mins
The sample space of rolling a die and tossing a coin simultaneously.
S={IT,2T,3T,4H,5H,6H,}
S = {IH,2H3H,AT,5T,6T}
S = {IH,IT,2H,2T,3H,3T,4H,4T,5H,5T,6H,6T}
S = {1H,2T,3H,4T,5H,6T}
Which of the following is a discrete random variable?
the average amount of electricity consumed
the average weight of female athletes
the percentage of the students who passed the exam
the number of persons eating seafood in a restaurant
A pair of dice is rolled. Let Y be the random variable denoting the sum of the points on the upturned faces of the dice. Find the values of the random variable Y.
2, 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12
1, 3, 5, 7, 9 and 11
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12
2, 4, 6, 8, 10 and 12
The following are continuous random variable EXCEPT
number of heads in 3 tosses of a fair coin
height of a person
income/money
weight of persons
A function whose value is a real number determined by each element in the sample space-the set of all possible outcomes of an experiment
random variable
probability distribution
density function
histogram
Which formula gives the probability distribution shown in the table at the right?
P(X)=61
P(X)=18X+2
P(X)=6X
P(X)=12X+1
Four coins are tossed. Let Y be the random variable representing the number of heads that occur. The probability distribution of the random variable Y is __________.
If P(X)=6X , what are the possible values of X for it to be a probability distribution?
1, 1, 2
2, 3, 4
0, 2, 3
1, 2, 3
If a pair of dice is rolled, which is not a possible value of the random variable for the sum of the points on the upturned faces of the dice?
1
4
7
11
What makes the distribution below a probability distribution?
The random variable is equally distributed.
The sum of all the values of P(X) is equal to one.
The values of the probability distribution are probabilities.
The values of the P(X) are numbers on the interval from 0 to 1.
A coffee shop serves three types of drinks: espresso, latte, and cappuccino. The probabilities that a randomly chosen customer orders these drinks are as follows:
Espresso: 0.4
Latte: 0.35
Cappuccino: 0.25
What is the expected number of customers who order a latte if 100 customers visit the coffee shop?
25
35
40
50
A factory produces bulbs, and the probability that a bulb lasts for different time intervals is given below:
Lasts less than 1 year: 0.1
Lasts between 1 and 2 years: 0.3
Lasts between 2 and 3 years: 0.4
Lasts more than 3 years: 0.2
If a quality check involves selecting 5 bulbs at random, what is the probability that exactly 2 bulbs last more than 3 years? (Assume independence.)
(a)
In a survey, participants are asked how many books they read last month. The results show that the random variable X can take values from 0 to 5 with the following probabilities:
P(X = 0) = 0.1
P(X = 1) = 0.2
P(X = 2) = 0.3
P(X = 3) = 0.2
P(X = 4) = 0.15
P(X = 5) = 0.05
Verify whether this is a valid probability distribution and explain why.
(a)
A coin is flipped 3 times. What is the probability of getting exactly 2 heads?
1/8
1/4
3/8
1/2
The probability that a student passes a subject is 0.7. If 10 students are randomly selected, what is the expected number of students who will pass?
3
5
7
10
