Go to a large parking lot or a large area where bicycles are parked. Choose a color or a manufacturer. Design a sampling scheme you can use to estimate the percentage of cars or bicycles of that color or model. In choosing the number to sample, consider the margin of error that will accompany your sample result. Now go through the entire area, actually taking a census, and compute the population percentage of cars or bicycles of that type.
a. Explain your sampling method and discuss any problems or biases you encountered in using it.
b. Construct an interval from your sample that almost surely covers the true population percentage with that characteristic. Does your interval cover the true population percentage you found when you took the census?
c. Use your experience with taking the census to name one practical difficulty with taking a census.