Suppose that 40% of a large population are in favor of candidate A. A pollster selects...
Suppose that 40% of a large population are in favor of candidate A. A pollster selects a random sample of 20 people and asks them about their opinion about the candidate. Let X be the number of people in favor of candidate A. What is E(X) and Var(X)?
Homework Answers
This is a binomial distribution.
n = 20
p = 0.4
E(X) = n * p = 20 * 0.4 = 8
Var(X) = n * p * (1 - p) = 20 * 0.4 * (1 - 0.4) = 4.8
Add Answer to:
Suppose that 40% of a large population are in favor of candidate
A. A pollster selects...
In a large population 40% votes for candidate A and 60% for candidate B. Suppose we...
In a large population 40% votes for candidate A and 60% for candidate B. Suppose we select at random 10 people. What is the probability that in this group exactly 4 people will vote for A?
Problem 1: A pollster would like to estimate the fraction p of people in a population...
Problem 1: A pollster would like to estimate the fraction p of people in a population who intend to vote for a particular candidate. How large must a random sample be in order to be at least 95% certain that the fraction of positive answers in the sample is within 0.02 of the true p
A population of 50 registered voters contain 30 in favor of Proposition 134 and 20 opposed....
A population of 50 registered voters contain 30 in favor of Proposition 134 and 20 opposed. An opinion survey selects a random sample of 4 voters from this population. (1) Calculate the probability that there will be no one in favor of Proposition 134 in the sample. (2) Calculate the probability that the sample contains exactly one pro 134 person. (3) Calculate the probability that there will be at least one person in favor of Proposition 134 in the sample.
Suppose that 35% of all voters prefer Candidate A. If 4 people are chosen at random...
Suppose that 35% of all voters prefer Candidate A. If 4 people are chosen at random for a poll, what is the probability that exactly 3 of them favor Candidate A?
Suppose that 75% of all voters prefer Candidate A. If 10 people are chosen at random...
Suppose that 75% of all voters prefer Candidate A. If 10 people are chosen at random for a poll, what is the probability that exactly 8 of them favor Candidate A?
Suppose that 60% of all voters prefer Candidate A.If 4 people are chosen at random for...
Suppose that 60% of all voters prefer Candidate A.If 4 people are chosen at random for a poll, what is the probability that exactly 2 of them favor Candidate A?
Suppose that of all voters in Florida, 40% (p=.4) are in favorite of candidate Brown for...
Suppose that of all voters in Florida, 40% (p=.4) are in favorite of candidate Brown for Governor. Pollsters take a sample of 2400 voters. What proportion of the sample would be expected to favor candidate Brown? (show your work)
1. The proportion of defective items in a large lot is p. Suppose a random sample of n items is s...
1. The proportion of defective items in a large lot is p. Suppose a random sample of n items is selected from the lot. Let X denote the mumber of defective itens in the sample and let denote the number of non-defective items. (a) Specify the distributions of X and Y, respectively. Are they independent? (b) Find E(X-Y) and var(X Y).
1. The proportion of defective items in a large lot is p. Suppose a random sample of n items...
Suppose it is reported that 60 % will vote for candidate A. You think this %...
Suppose it is reported that 60 % will vote for candidate A. You think this % is different in your neighborhood, so you decide to randomly sample 121 people and ask them if they will vote for candidate A. Is the sample size large enough ? μ ˆ p = σ ˆ p = Suppose we find from our sample that 119 will vote for candidate A. Give ˆ p What is the probability that at least 119 people will...
The proportion of defective items in a large lot is p. Suppose a random sample of...
The proportion of defective items in a large lot is p. Suppose a random sample of n items is selected from the lot. Let X denote the number of defective items in the sample and let Ydenote the number of non-defective items (a) Specify the distributions of X and Y , respectively. Are they independent? (b) Find E(X −Y) and var(X −Y).
In a large population 40% votes for candidate A and 60% for candidate B. Suppose we select at random 10 people. What is the probability that in this group exactly 4 people will vote for A?
Problem 1: A pollster would like to estimate the fraction p of people in a population who intend to vote for a particular candidate. How large must a random sample be in order to be at least 95% certain that the fraction of positive answers in the sample is within 0.02 of the true p
Suppose that 35% of all voters prefer Candidate A. If 4 people are chosen at random for a poll, what is the probability that exactly 3 of them favor Candidate A?
1. The proportion of defective items in a large lot is p. Suppose a random sample of n items is selected from the lot. Let X denote the mumber of defective itens in the sample and let denote the number of non-defective items. (a) Specify the distributions of X and Y, respectively. Are they independent? (b) Find E(X-Y) and var(X Y).
1. The proportion of defective items in a large lot is p. Suppose a random sample of n items...
Most questions answered within 3 hours.
-
Where is the error in this code sequence?
String s1 = "Hello";
String s2 = "ello";...
asked 11 months ago -
Financial data for Joel de Paris, Inc., for last year
follow:
Joel de Paris, Inc.
Balance...
asked 11 months ago -
Consider this reaction:
Al2(SO4)3 (aq)+ BaCl3
(aq) Al2Cl6 (aq)- +
3BaSO4(s) . What is the...
asked 11 months ago -
Suppose that Savneet is considering increasing her
recent random sample from 20 car rentals to 40...
asked 11 months ago -
Trucks arrive at an unloading terminal at an average rate of 120
per hour.
Trucks arrive...
asked 11 months ago -
Why are methanol and ethanol completely soluble in water while
octanol is not very little soluble....
asked 11 months ago -
A facilities manager at a university reads in a research report
that the mean amount of...
asked 11 months ago -
When the CuSO4 is rehydrated by adding water to the anhydrous
compound, is this an endothermic...
asked 11 months ago -
A ray of sunlight is passing from diamond into crown glass; the
angle of incidence is...
asked 11 months ago -
A block of mass 0.249 kg is placed on top of a light, vertical
spring of...
asked 11 months ago -
how do the kidneys compensate in the presences of acidosis
a) trigger hyperventilate
b) reserve acid...
asked 11 months ago -
Question 501 pts
The rental rate of capital to the firm increases. Which of the
following...
asked 11 months ago