Assignment # 1 - Sampling Error
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Sampling Error Grading Basis: Part 1, each of the six (6) Sampling Error calculations (Blue, Red, Yellow, Orange, Green & Brown) are worth 14 points each out of 84 possible points. Part 2 is worth 16 points out of 16 points. So the total possible points are 100. This assignment is worth 5 points of your final grade. See Syllabus Grading Basis. Example: 100 (possible total assignment points) - 16 points (Part 2 item 1 wrong answer) = 84 (assignment grade) x .05 = 4.2 total grade points
Assignment Guidelines
Assignment 1 is about the margin of error. Every survey question has a response, usually presented as a percent (%). An example from a previous survey is shown below: "Would you support a 1/8 cent sales tax increase to be used to purchase open space and parks in Coconino County? Yes 57% No 41% Undecided 2% The margin of error was +/- 3% on this survey. So what does this mean? With any question the accuracy of the answer is determined by the sample size and the response rate. So a response of 57% with a +/- 3% margin of error really means that with a 97% confidence level, the response would fall between 54% and 60%. The answer of 57% is a midpoint. This applies to all surveys.
See the text: What Are the Chances: Unit 2.4. (pages 134 to 143) Part 1 Calculate the Margin of Error Example: To calculate a percentage: If the total M&M's in your package are 56 and the total Blue M&M's in your package are 20 pieces, then 20 divided by 56 = 0.357, move the decimal over two places, and you get +/- 35.7%, then divide by 2 for the correct answer of +/- 17.8%, Example: M&M web site (blue) 24% - Your M&M sample Blue _35.7 % = _11.7_ divided by 2 = Margin of error +/- _5.85 % NOTE: Do NOT round your answers and only include the first two decimal places! Conduct the following sampling error exercise.
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1. Purchase a package of M & M plain (1.69 oz / 47.9 g) chocolate candy.
3. Using the following information on the percentages of each color of M&M plain candy in each package.
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4. Now compare your counts (%) to those of the M & M web site.
5. Using the table below, calculate 
your sampling error as a
(+/-)
percentage (%) for each color.
Sample Format: Submit your assignment using this table format.
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M&M Colors |
M&M Web Site Count (%) |
M&M Count (%) from your sample |
Sampling Error (+/-) |
| Blue | |||
| Red | |||
| Yellow | |||
| Orange | |||
| Green | |||
| Brown |
6. Include your total M&M count (total M&M pieces).
7. Enjoy your M&M's
Part 2 Interpret the Margin of Error
Applying your understanding from Part 1 above and using the MoE information provided below for the CNN survey. Identify the correct range for the Joe Smith (D) and Willaim Brown (R) results using the following format:
Joe Smith 50 points Range ___ to ___
William Brown 46 points Range ___ to ___
MoE 4.0
1) Please answer the following question: According to the data provided, who is ahead in the poll?
CNN dated August 16, 2020
The study was conducted for CNN via telephone by SSRS, an independent research company. Interviews were conducted from August 12-15, 2020 among a sample of 1,108 respondents. The landline total respondents were 386 and there were 722 cell phone respondents. The margin of sampling error for total respondents is +/- 4 at the 95% confidence level. The design effect is 1.62. More information about SSRS can be obtained by visiting www.ssrs.com.
Reference: SSRS Research Refined (August 16, 2020). CNN Overview. https://cdn.cnn.com/cnn/2020/images/08/16/rel8a.-.2020.pdf
Polling Data
Poll |
Date |
Sample |
MoE |
Smith (D) |
Brown (R) |
Spread |
8/12 - 8/15 |
987 RV |
4.0 |
50 |
46 |
Smith +4 |
MoE (Margin of Error)
Submit this assignment to the course Instructor as an
email message.
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