Homework
M3A1 Homework
Visit Khan Academy's web site. Watch the video on the margin of error 1 and margin of error 2.
200word
1. What is a margin of error?
2. Watch the video on polling and read the article on polling. Then watch the video and read about the limitations of public opinion.
a. What are the benefits and limitations of using public opinion in research?
b. How do you generalize survey results?
c. Can you describe survey bias?
3. Optional extra credit -Please conduct a hypothesis test and complete steps (a-f) for the following:
Fidelity Investments is a Boston institution that is “among the most diversified financial services companies in the world, offering a full range of product solutions for individual investors, employers, institutions, and intermediaries. Fidelity has $6.8 billion in assets under administration, including managed assets of $2.4 billion, as of December 31, 2018” Fidelity operates service centers in various cities that customers can call to get answers to questions about their investments. Previously, the company studied the distribution of time required for each call. It found that calls are normally distributed, with a mean equal to 540 seconds. The call center manager in Provo, Utah, has selected a random sample of 50 calls and wants to determine whether the mean call time is now less than 540 seconds after a training program given to call center employees. She can test whether the time has decreased by using the following steps:
A. Set up a hypothesis
B. Set up a suitable significance level
C. Determine a suitable test statistic
D. Determine the critical region
E. Perform computations
F. Make decision to accept or reject hypothesis
Reference
Fidelity Investments – “Fidelity by the Numbers: Corporate Statistics”
Margin of error 1 : https://www.khanacademy.org/math/statistics-probability/confidence-intervals-one-sample/estimating-population-proportion/v/margin-of-error-1
Margin of error 2: https://www.khanacademy.org/math/statistics-probability/confidence-intervals-one-sample/estimating-population-proportion/v/margin-of-error-2