A recent survey of 7 social networking sites has a

Annette Sabin 2021-12-20 Answered
A recent survey of 7 social networking sites has a mean of 14.69 million visitors for a specifie month. The standard deviation was 4.4 millon. Find the 95% confidence interval of the true mean. Assume the variable is normally distributed. Round your answers to two decimal places.

Expert Community at Your Service

  • Live experts 24/7
  • Questions are typically answered in as fast as 30 minutes
  • Personalized clear answers
Learn more

Solve your problem for the price of one coffee

  • Available 24/7
  • Math expert for every subject
  • Pay only if we can solve it
Ask Question

Expert Answer

Jeremy Merritt
Answered 2021-12-21 Author has 2507 answers
\(\displaystyle{n}={7}\)
\(\displaystyle\hat{{{x}}}={14.69}\)
\(\displaystyle{s}={4.4}\)
\(\displaystyle{95}\%\) CI of mean
\(\displaystyle\mu=\hat{{{x}}}\pm{\frac{{{z}\cdot{s}}}{{\sqrt{{n}}}}}\)
\(\displaystyle=\mu={14.69}\pm{\frac{{{1.96}\cdot{4.4}}}{{\sqrt{{7}}}}}\)
\(\displaystyle={14.69}\pm{3.25}\)
\(\displaystyle={\left({11.44},\ {17.94}\right)}\)
Not exactly what you’re looking for?
Ask My Question
0
 
Steve Hirano
Answered 2021-12-22 Author has 4237 answers
Why z=1.96?
0
nick1337
Answered 2021-12-28 Author has 9467 answers
Because at 95% CI, z=1.96
0

Expert Community at Your Service

  • Live experts 24/7
  • Questions are typically answered in as fast as 30 minutes
  • Personalized clear answers
Learn more

Relevant Questions

asked 2021-09-18
In a survey of 3307 adults, 1464 say they startied paying bills online in the last year.
Construct a \(\displaystyle{99}\%\) confidence interval for the population proportion.
Interpret your results. Choose the correct answer below.
A) With \(\displaystyle{95}\%\) confidence, it can be said that the population proportion of adults who say they have started paying bills online in the last year is between the endpoints of the given confidence interval
B) The endpoints of the given confidence interval show that adults pay bills online \(\displaystyle{99}\%\) of the time.
C) With \(\displaystyle{99}\%\) confidence, it can be said that the sample proportion of adults who say they have started paying bills online in the last year is between the endpoints of the given confidence interval.
asked 2021-09-18
In a survey of 2695 adults, 1446 say they have started paying bills online in the last year.
Construct a \(\displaystyle{99}\%\) confidence interval for the population proportion.
Interpret your results. Choose the correct answer below.
A) With \(\displaystyle{95}\%\) confidence, it can be said that the sample proportion of adults who say they have started paying bills online in the last year is between the endpoints of the given confidence interval
B) With \(\displaystyle{99}\%\) confidence, it can be said that the population proportion of adults who say they have started paying bills online in the last year is between the endpoints of the given confidence interval.
C) The endpoints of the given confidence interval show that adults pay bills online \(\displaystyle{99}\%\) of the time.
asked 2021-09-23
In a survey of 2085 adults in a certain country conducted during a period of economic?
Uncertainty, \(\displaystyle{63}\%\) thought that wages paid to workers in industry were too low. The margin of error was 8 percentage points with \(\displaystyle{90}\%\) confidence.
For parts (1) through (4) below, which represent a reasonable interpretation of the survey results. For those that are not reasonable, explain the flaw.
1) We are \(\displaystyle{90}\%\) confident \(\displaystyle{63}\%\) of adults in the country during the period of economic uncertainty felt wages paid to workers in industry were too low.
A) The interpretation is reasonable.
B) The interpretation is flawed. The interpretation provides no interval about the population proportion.
C) The interpretation is flawed. The interpretation sugguests that this interbal sets the standard for all the other intervals, which is not true.
D) The interpretation is flawed. The interpretation indicates that the level of confidence is varying.
2) We are \(\displaystyle{82}​\%\) to \(\displaystyle{98}​\%\) confident \(\displaystyle{63}​\%\) of adults in the country during the period of economic uncertainty felt wages paid to workers in industry were too low. Is the interpretation​ reasonable?
A) The interpretation is reasonable.
B) The interpretation is flawed. The interpretation provides no interval about the population proportion.
C) The interpretation is flawed. The interpretation sugguests that this interbal sets the standard for all the other intervals, which is not true.
D) The interpretation is flawed. The interpretation indicates that the level of confidence is varying.
3) We are \(\displaystyle{90}\%\) confident that the interval from 0.55 to 0.71 contains the true proportion of adults in the country during the period of economic uncertainty who believed wages paid to workers in industry were too low.
A) The interpretation is reasonable.
B) The interpretation is flawed. The interpretation provides no interval about the population proportion.
C) The interpretation is flawed. The interpretation sugguests that this interbal sets the standard for all the other intervals, which is not true.
D) The interpretation is flawed. The interpretation indicates that the level of confidence is varying.
4) In \(\displaystyle{90}\%\) of samples of adults in the country during the period of economic uncertainty, the proportion who believed wages paid to workers in industry were too low is between 0.55 and 0.71.
A) The interpretation is reasonable.
B) The interpretation is flawed. The interpretation provides no interval about the population proportion.
C) The interpretation is flawed. The interpretation sugguests that this interbal sets the standard for all the other intervals, which is not true.
D) The interpretation is flawed. The interpretation indicates that the level of confidence is varying.
asked 2021-09-22

A certain reported that in a survey of 2006 American adults, \(\displaystyle{24}\%\) said they believed in astrology.
a) Calculate a confidence interval at the \(\displaystyle{99}\%\) confidence level for the proportion of all adult Americans who believe in astrology. (Round your answers to three decimal places.)
(_______, _______)
b) What sample size would be required for the width of a \(\displaystyle{99}\%\) CI to be at most 0.05 irresoective of the value of \(\displaystyle\hat{{{p}}}\)? (Round your answer up to the nearest integer.)

asked 2021-09-16

A survey of several 10 to 11 year olds recorded the following amounts spent on a trip to the mall:
$19.17,$21.18,$20.38,$25.08
Construct the \(\displaystyle{90}\%\) confidence interval for the average amount spent by 10 to 11 year olds on a trip to the mall. Assume the population is approximately normal.
Copy Data
Step 4 of 4 : Construct the \(\displaystyle{90}\%\) confidence interval. Round your answer to two decimal places.

asked 2021-08-02
Survey A asked 1000 people how they liked the new movie Avengers: Endgame and \(\displaystyle{88}\%\) said they did enjoy it.
Survey B also concluded that \(\displaystyle{82}\%\) of people liked the move but they asked 1600 total moviegoers.
Which of the following is true about this comparison?
1. The margin of error is the same for both.
2. The confidence interval is smaller for Survey B.
3. Increasing the number of people asked does not change the \(\displaystyle{95}\%\) confidence interval.
4. Survey A is more accurate since the percentage is higher.
5. Survey A has more approvals than Survey B.
6. Survey A is better than Survey B since it has a higher percentage.
asked 2021-08-08
Survey A asked 1000 people how they liked the new movie Avengers: Endgame and \(\displaystyle{88}\%\) said they did enjoy it.
Survey B also concluded that \(\displaystyle{82}\%\) of people liked the move but they asked 1600 total moviegoers.
Which of the following is true about this comparison?
The margin of error is the same for both.
The confidence interval is smaller for Survey B.
Increasing the number of people asked does not change the \(\displaystyle{95}\%\) confidence interval.
Survey A is more accurate since the percentage is higher.
Survey A has more approvals than Survey B.
Survey A is better than Survey B since it has a higher percentage.
...