Question
In: Statistics and Probability
A newspaper reported that 48% of smartphone purchases made by people with incomes between $35,000 to...
A newspaper reported that 48% of smartphone purchases made by people with incomes between $35,000 to $50,000 were a certain kind of phone.
(a) If the story is based on a sample of 250 purchases, then should we conclude that this type of phone was getting less than half of the market at that time?
(b) How large a sample is needed for the 95% confidence interval for the population proportion to exclude 50%?
Please show and explain all work.
Solutions
Expert Solution
Answer:
Given that:
A newspaper reported that 48% of smartphone purchases made by people with incomes between $35,000 to $50,000 were a certain kind of phone.
(a) If the story is based on a sample of 250 purchases, then should we conclude that this type of phone was getting less than half of the market at that time?
Under 
the test statistics is
Accept
at
Hence we conclude that this type of phone is getting half of the material
(b) How large a sample is needed for the 95% confidence interval for the population proportion to exclude 50%?
We require 
squaring both sides
we required to 
orchestra answered 1 year agoRelated Solutions
it has been reported that 48% of people text and drive. A random sample of 60...
it has been reported that 48% of people text and drive. A random
sample of 60 drivers is drawn. Find the probability that the
proportion of people in the sample who text and drive is less than
0.498.
The Wall Street Journal reported that 33% of taxpayers with adjusted gross incomes between $30,000 and...
The Wall Street Journal reported that 33% of taxpayers with adjusted gross incomes between $30,000 and $60,000 itemized deductions on their federal income tax return. The mean amount of deductions for this population of taxpayers was $15,071. Assume that the standard deviation is 82,790. Use 2-table. a. What is the probability that a sample of taxpayers from this income group who have itemized deductions will show a sample mean within $200 of the population mean for each of the following sample...
The Wall Street Journal reported that 33% of taxpayers with adjusted gross incomes between $30,000 and...
The Wall Street Journal reported that 33% of taxpayers with adjusted gross incomes between $30,000 and $60,000 itemized deductions on their federal income tax return. The mean amount of deductions for this population of taxpayers was $17,696. Assume that the standard deviation is o = $2,256. Use z-table. a. What is the probability that a sample of taxpayers from this income group who have itemized deductions will show a sample mean within $229 of the population mean for each of the...
The Wall Street Journal reported that 33% of taxpayers with adjusted gross incomes between $30,000 and...
The Wall Street Journal
reported that 33% of taxpayers with adjusted gross incomes between
$30,000 and $60,000 itemized deductions on their federal income tax
return. The mean amount of deductions for this population of
taxpayers was $17,743. Assume that the standard deviation is σ =
$2,581. Use z-table.
a. What is the probability that a sample of taxpayers from this
income group who have itemized deductions will show a sample mean
within $227 of the population mean for each of...
The Wall Street Journal reported that of taxpayers with adjusted gross incomes between and itemized deductions...
The Wall Street Journal reported that of taxpayers with adjusted
gross incomes between and itemized deductions on their federal
income tax return. The mean amount of deductions for this
population of taxpayers was . Assume that the standard deviation is
. Use z-table. a. What is the probability that a sample of
taxpayers from this income group who have itemized deductions will
show a sample mean within of the population mean for each of the
following sample sizes: , ,...
The Wall Street Journal reported that 33% of taxpayers with adjusted gross incomes between $30,000 and...
The Wall Street Journal reported that 33% of taxpayers with
adjusted gross incomes between $30,000 and $60,000 itemized
deductions on their federal income tax return. The mean amount of
deductions for this population of taxpayers was $16,675 . Assume
that the standard deviation is $2,645 . Use z-table. a. What is the
probability that a sample of taxpayers from this income group who
have itemized deductions will show a sample mean within $194 of the
population mean for each of...
The Wall Street Journal reported that 33% of taxpayers with adjusted gross incomes between $30,000 and...
The Wall Street Journal reported that 33% of taxpayers
with adjusted gross incomes between $30,000 and $60,000 itemized
deductions on their federal income tax return. The mean amount of
deductions for this population of taxpayers was $16,928 . Assume
that the standard deviation is $2,903.
(a) What is the probability that a sample of taxpayers from this
income group who have itemized deductions will show a sample mean
within $151 of the population mean for each of the following sample...
The Wall Street Journal reported that of taxpayers with adjusted gross incomes between and itemized deductions...
The Wall Street Journal reported that of taxpayers with adjusted
gross incomes between and itemized deductions on their federal
income tax return. The mean amount of deductions for this
population of taxpayers was . Assume that the standard deviation is
. Use z-table. a. What is the probability that a sample of
taxpayers from this income group who have itemized deductions will
show a sample mean within of the population mean for each of the
following sample sizes: , ,...
The Wall Street Journal reported that 33% of taxpayers with adjusted gross incomes between $30,000 and...
The Wall Street Journal reported that 33% of taxpayers
with adjusted gross incomes between $30,000 and $60,000 itemized
deductions on their federal income tax return. The mean amount of
deductions for this population of taxpayers was $15,968. Assume
that the standard deviation is $2,190. Use z-table.
a. What is the probability that a sample of
taxpayers from this income group who have itemized deductions will
show a sample mean within $184 of the population mean for each of
the following...
1) The Wall Street Journal reported that of 33% taxpayers with adjusted gross incomes between $30,000...
1) The Wall Street Journal reported that of 33% taxpayers with
adjusted gross incomes between $30,000 and $60,000 itemized
deductions on their federal income tax return. The mean amount of
deductions for this population of taxpayers was $15,772. Assume
that the standard deviation is $2,681. Use z-table.
a. What is the probability that a sample of taxpayers from this
income group who have itemized deductions will show a sample mean
within of the population mean for each of the following...
ADVERTISEMENT
ADVERTISEMENT
Latest Questions
- In the vertices of a square of side 2x10 ^ -7 four protons are placed. A...
- Analyze the distinction between program evaluation and policy analysis, and why governmental organizations engage in such...
- After reading an article about activity-based costing in a trade journal for the furniture industry, Santana...
- Answer question #1 of the Johnstown Foundry, Inc. Ethical Dilemma (found at the end of Chapter...
- examples of an insulator, a conductor, a semiconductor are respectively?
- How do agencies such as Fannie Mae and Freddie Mac allow individual mortgage holders to collectively...
- Often times employees develop ownership in the organization and feel work and materials are the product...
ADVERTISEMENT