Why might people get different results?

  • Discussion Prompt 1

Spend some time looking at the vehicles on the road. Look at the first 40 vehicles that drive by. Take note of the number of vehicles that are cars (sedans). Use the data you collect to construct confidence interval estimates of the proportion of vehicles that are cars (rather than trucks, vans, etc.). Report your confidence interval to the group.

Why might people get different results? Is your sample likely a good representation of the total population of all vehicles? Why or why not? Make sure you show all your work and explain each of your steps to arrive at the confidence interval.

  • Discussion Prompt 2

Take your survey data and code the gender question as Male=0 and Female=1. Suppose we hypothesize that women are more likely to respond to surveys than men are. Specifically, we believe that more than 55 percent of all respondents are women (this equates to the proportion of the gender variable to be greater than 0.55). Use the methods learned this week to test this hypothesis.

Make sure you go through the 6-step process of testing the hypothesis.

Present your results and discuss why you rejected, or failed to reject the null hypothesis.