The average numbers of days it took Chicago€™s Department of Streets & Sanitation to respond to requests to fix street lights €œAll Out€ (three or more lights) are described by the density histogram in Fig. 97 for each of the weeks in 2012 and 2013.

a. Identify the class that contains the 50th percentile, which is a measure of the center. Are observations in the class typical values? Explain.
b. From inspecting the histogram, a student concludes that for 2015, the average response time will be less than 2 days for 2% of the weeks. What would you tell the student?
c. The department has a target that the average time to respond to street lights €œAll Out€ requests made in a given week be less than 4 days. Find the proportion of observations that are less than 4 days.
d. For what proportion of the weeks was the average response time at least 4 days? One of the bars in the density histogram was left blank on purpose.
e. Suppose the department changes the target to be less than 3 days. Find the proportion of observations that are less than 3 days.

Transcribed Image Text:

Average Response Time to Fix Street Lights 0.6 0.5 0.4 0.3 0.2 0.1 0.53 0.02 0.37 0.07 Days