WorksheetsMarch 5 test: Probability Distributions
Total questions: 15
Worksheet time: 3hrs 30mins
The equation for variance of a probability distribution is ...
μ = ΣX/N
σ2 = npq
σ2 = Σ(X - μ)2/N
none of these
The equation for mean of a probability distribution is ...
μ = ΣX/N
μ = ΣX.P(X)
σ2 = Σ(X - μ)2/N
none of these
The equation for mean of a binomial distribution is ...
μ = np
μ = ΣX.P(X)
σ2 = Σ(X - μ)2/N
none of these
Choose the best answer. The probability distribution shown represents ...
The number of boys for a family with 3 children
Both of these
The number of tails after flipping a coin 3 times
Neither of these
What is the mean of the distribution shown?
1.5
0.25
2.0
none of these
If μ = 2.0, what is the variance of the distribution shown?
0.5
0.7
4.5
none of these
If μ = 100 and σ2 = 9 for a probability distribution, what is the standard deviation?
3
10
81
none of these
In a large bag of marbles, 30% are red, 20% are blue, and 50% are green. What is the chance that exactly 3 of 6 randomly chosen marbles are green?
31%
33%
50%
none of these
A student randomly guesses at all 8 questions in a quiz. 4 questions are true/false, 4 are multiple-choice quiz with 5 choices for each question. Is this a binomial experiment?
Yes
No
Not enough information
A student takes an 8 question multiple-choice quiz with 5 choices for each question. If the student randomly guesses at each question, he has the greatest probability of getting exactly how many questions correct?
1
4
7
none of these
If 50% of Americans approve of Biden’s job performance and polls of 100 randomly chosen Americans are conducted, what is the standard deviation in the number that approve of Biden’s job performance?
25
7.1
5
none of these
You and 999 others each buy $2 lotto tickets; one lucky winner gets $1,800. What is the expected value of your ticket?
$0.50
–$0.20
–$0.13
none of these
A university has 3,000 students of which 20% are male. If numerous classes of 25 students are chosen at random, find the mean number of female students in those classes.
5
20
2,400
none of these
0
0.1
0.2
not enough information
The failure rate for the bar exam in Florida is 41%. If 475 take the bar exam, what is the mean (expected value) for the number of failures?
194.8
221.3
90.7
153.8
