SOLUTION: The Pew Research Center conducted a survey of 1007 adults and found that 856 of them know what Twitter is.
a.What is the point estimate for the number of adults who know what Tw
Algebra.Com
Question 974214: The Pew Research Center conducted a survey of 1007 adults and found that 856 of them know what Twitter is.
a.What is the point estimate for the number of adults who know what Twitter is?
b.Use a 0.01 level of significance to test the claim that more than 75% of adults know what Twitter is.
State the null and alternative hypotheses:
Calculate the test statistic:
Fine the p-value:
Decision:
Conclusion:
Answer by jim_thompson5910(35256) (Show Source): You can put this solution on YOUR website!
(a)
Given:
x = 856
n = 1007
p-hat = x/n
p-hat = 856/1007
p-hat = 0.85004965243297
The point estimate is approximately 0.85004965243297
--------------------------------------------------------------------------------------------
(b)
Given:
x = 856
n = 1007
p = 0.75
phat = 0.85004965243297 (found in part a)
alpha = 0.01
Hypothesis:
H0: p = 0.75
H1: p > 0.75 (claim)
Standard Error:
SE = sqrt(p*(1-p)/n)
SE = sqrt(0.75*(1-0.75)/1007)
SE = 0.0136453883651
Test Statisic:
z = (phat - p)/SE
z = (0.85004965243297 - 0.75)/0.0136453883651
z = 7.3321220148531
p-value
normalcdf(7.3321220148531, 99999) = 1.14 * 10^(-13)
The p-value is so very small that it's effectively 0.
No matter what the significance level is, we have statistically significant evidence to reject H0.
Decision: Reject the null hypothesis
Conclusion: There is enough significant evidence to conclude that the population proportion who are familiar with twitter is over 75%
------------------------------------------------------------------------------------------------------------------------
If you need more one-on-one help, email me at jim_thompson5910@hotmail.com. You can ask me a few more questions for free, but afterwards, I would charge you ($2 a problem to have steps shown or $1 a problem for answer only).
Alternatively, please consider visiting my website: http://www.freewebs.com/jimthompson5910/home.html and making a donation. Any amount is greatly appreciated as it helps me a lot. This donation is to support free tutoring. Thank you.
Jim
------------------------------------------------------------------------------------------------------------------------
RELATED QUESTIONS
According to a Pew Research Center nationwide telephone survey of adults conducted... (answered by stanbon)
When an adult is randomly selected, there is an 85% chance that this person knows what... (answered by greenestamps)
3. According to a PEW* Research Center survey, the mean student loan at graduation is... (answered by ikleyn)
A market research group conducted a survey of 1000 customers and reported that 720... (answered by rfer)
According to a survey, 40% of adults are against using animals for research. Assume that... (answered by ikleyn)
What is the ones's digit of... (answered by Alan3354)
A survey was conducted and found that 15/17 students have a smart phone. Of these, 7/17 (answered by ikleyn)
In a nationwide telephone poll of 1500 U.S. adults conducted for the freedom Forum by the (answered by bobbiensam)
In a poll conducted by the Pew Research Center in 2003, a national sample of adults... (answered by stanbon)