Smoke Detector Simulation (1-prop z)
A 1996 report from the U.S. Consumer Product Safety Commission claimed that at least 90% of all American homes have at least one smoke detector. A city’s fire department has been running a public safety campaign about smoke detectors consisting of posters, billboards, and ads on radio and TV and in the newspaper. The city wonders if this concerted effort has raised the local level above the 90% national rate. Building inspectors visit 400 randomly selected homes and find that 376 have smoke detectors.
In the dot plot below, each dot represents the proportion of homes (out of 400) that have smoke detectors, under the assumption that 90% of homes have them. There are 100 simulated trials in the plot below.
Does this suggest that the local rate is higher than the national rate?