https://www.transtats.bts.gov/Homepage.asp According to the Bureau of Statistics, about 20% of all US flights are delayed by 15 minutes or more. Use the variable ARR_DEL15 from the Oregon Flights dataset to test whether flights to and from Oregon airports have a proportion of delayed flights that is other than 0.20. Data attached
Step 1: Summarize your Data
- Create a pivot table to obtain the count of objects that have the desired characteristic within your categorical variable. Calculate the sampled proportion from this data.
- Save your table to copy into your analysis.
- Optional: Create a barchart of your variable and include that in your analysis instead.
Step 2: Conduct a hypothesis test and calculate a 95% confidence interval for p
- Use your option's question of interest to state the null and alternative hypotheses and to obtain the claimed proportion.
- Use your sampled proportion and sample size to calculate the test statistic and obtain a p-value.
- Use your sampled information to calculate a 95% confidence interval.
- Save and show your work for your post.
Ways to show your work:
- Take a screenshot of your excel workbook. Only the work part not the entire screen.
- Take a screenshot of handwritten work on a tablet.
- Neatly hand-write your formulas on paper take a picture with your phone and upload the image within your post. Image needs to .jpeg. (please no words/sentences)
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Step 3: Explain your analysis
- Use the same headers as listed below (e.g., "State and Visualize" Checking Conditions") in your post.
- Answer each question/prompt in the bulleted list below each heading in your post.
- For the math related questions, please show your work or excel functions you used to find your answers.
State and Visualize
- State the question of interest.
- Provide a table of counts or a graphical display of your sampled data.
Plan
- State the null and alternative hypotheses to answer the question of interest.
- Explain whether it is reasonable to assume the sample provides an unbiased representation of the population of interest.
- Determine whether the sample size condition is met so that we can expect to be normal. Heads up! this is not n greater than or equal to 30!
Solve
- Calculate the test statistic. Show work.
- What is the p-value? Is it one or two sided?
- Calculate a 95% confidence interval for p. Show work.
Conclude
Write a four-part conclusion describing the results.- Provide a statement in terms of the alternative hypothesis.
- State whether (or not) to reject the null (use alpha of 0.05)
- Give an interpretation of the point and interval estimate.
- Include context and practical insights or plausible implications from the results of the data.