Question

In a certain town, there are 4,000 registered voters, of whom 1,600 are Democrats. A survey organization is about to take a random sample of 100 registered voters.

(a) There is about a 50-50 chance that the percentage of Democrats in the sample will be bigger than _____.

(b) Find the expected value for the sample percentage,

(c) Find the standard error for the sample percentage.

(d) Find the chance that 30% or more of the people in sample are Democrats.

(e) True or false: If a large sample were taken, the standard error for the sample percentage would have been smaller

Answer #1

In a survey of 500 residents in a certain town, 312 said they
were opposed to constructing a new shopping mall. Can you conclude
that at least 60% of the residents in this town are opposed to
constructing a new shopping mall? Use ? = 0.05.
a. Find 95% confidence interval and use it to test the
hypothesis.
b. Clearly write your conclusion.
c. If the true percentage of town residents opposing the new
shopping mall is 65%, what is...

You want to estimate the proportion of American voters who are
optimistic about the state of the economy. How large a sample would
be needed to ensure a 95% confidence level that the actual
population proportion of American voters will be no more than 3
percentage points from the sample proportion?(hint, no information
about ? ^)
(a) 1506
(b) 1068
(c) 3152
(d) 938
Suppose at the 90% confidence level we calculate a confidence
interval described by 23.8<?<26.2. Which of...

Question 1.
A) In a simple random sample of 100 graduates from a certain
college, 48 were earning $50,000 a year or more. Estimate a 90%
confidence interval for the proportions of all graduates of that
college earning $50,000 a year or more.
A box contains a large number of red and blue tickets; the
proportion of red tickets is known to be 50%. A simple random
sample of 100 tickets is drawn from the box. Say whether each of...

A student has the following assignment grades: 85, 92, 72, 69,
74, 96, 83, 76, 72, 97. Find the mean, mode, and the five-number
summary. Round to one decimal
Find the mean and the standard deviation of the following quiz
scores:
21, 20, 23, 15, 16. Round to one decimal.
15,000 students take a national test. The results are normally
distributed with a mean of 400 and a standard deviation of 120.
Approximately how many students scored between 400 and...

Answer the question.
CHAPTER 8: ESTIMATION AND CONFIDENCE INTERVALS
1. As degrees of freedom increase, the t-distribution approaches
the:
A. binomial distribution
B. exponential distribution
C. standard normal distribution
D. None of the above
2. Given a t-distribution with 14 degrees of freedom, the area
left of - 1.761 is
A. 0.025
B. 0.05
C. 0.10
D. 0.90
E. None of the above
3. 100 samples of size fifty were taken from a population with
population mean 72. The sample...

2)McBeans magazine recently published a news article about
caffeine consumption in universities that claims that 80% of people
at universities drink coffee regularly. Moonbucks, a popular coffee
chain, is interested in opening a new store on UBC campus. After
reading McBeans' article, they will consider opening a store in UBC
if more than 80% of the people in UBC drink coffee regularly. A
random sample of people from UBC was taken, and it was found that
680 out of 810...

1.The sample mean is an unbiased estimator for
the population mean. This means:
The sample mean always equals the population mean.
The average sample mean, over all possible samples, equals the
population mean.
The sample mean will only vary a little from the population
mean.
The sample mean has a normal distribution.
2.Which of the following statements is
CORRECTabout the sampling distribution of the
sample mean:
The standard error of the sample mean will decrease as the
sample size increases....

2) A market research company wishes to find out which of two
internet search engines the
population of students at a university prefers to use: Google or
MSN Search. A random sample
of students is selected, and each one is asked to search for a
certain subject using Google and
then MSN, or vice versa. The order of the two searches was
determined at random. They then
indicate which internet search engine they prefer. What type of
study is this?...

1. According to the Bureau labor of statistics, the mean weekly
earnings for people working in a sales-related profession in 2010
was $660. Assume the weekly earnings are approximately normally
distributed with a standard deviation of $75. If a salesperson was
randomly selected, find the probability that his or her weekly
earnings are at most $40.(choose the best answer)
a. .0004
b. .4246
c. .0478
d. .4182
e. .6255
2. A film distribution manager calculates that 8% of the films...

2.Calculating probabilities and quantiles with RUse R and your
knowledge of the common probability densities we’ve talked about
inclass to answer the following questions.(a) A representative from
PSU’s athletic department randomly selects PSU studentsoutside the
HUB to see if they attended the last home men’s basketball game.
Letp, the probability she selects such a person, be equal to 0.001,
and letXdenotethe number of people she must survey until she finds
such a person.i. What is the probability the representative must...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 57 seconds ago

asked 8 minutes ago

asked 19 minutes ago

asked 30 minutes ago

asked 44 minutes ago

asked 44 minutes ago

asked 49 minutes ago

asked 54 minutes ago

asked 55 minutes ago

asked 56 minutes ago

asked 1 hour ago

asked 1 hour ago