Chapter 3.3, Problem 43E

According to a Los Angeles Times study of more than 1 million medical dispatches from 2007 to 2012, the 911 response time for medical aid varies dramatically across Los Angeles (La Times website, November 2012). Under national standards adopted by the Los Angeles Fire Department, rescuers are supposed to arrive within six minutes to almost all medical emergencies. But the Times analysis found that in affluent hillside communities stretching from Griffith Park to Pacific Palisades, firefighters failed to hit that mark nearly 85% of the time.

The following data show the response times, in minutes, for 10 emergency calls in the Griffith Park neighborhood.

11.8

10.3

10.7

10.6

11.5

8.3

10.5

10.9

10.7

11.2

Based on this sample of ten response times, compute the descriptive statistics in parts (a) and (b) and then answer the questions in parts (c) and (d):

1. a. Mean, median, and mode
2. b. Range and standard deviation
3. c. Should the response time of 8.3 minutes be considered an outlier in comparison to the other response times?
4. d. Do the response times indicate that the city is meeting the national standards? Should the city consider making changes to its response strategies? Would adding more stations to areas in the city be a practical solution? Discuss.