In 2013, 4579 runners completed the Great Cow Harbor 10K Run in Northport, New York. Their ages (in years) are de- scribed by the density histogram in Fig. 27.

a. Find the probability that a randomly selected runner€™s age was between 10 and 69 years, inclusive.
b. Find the probability that a randomly selected runner€™s age was at most 9 years OR at least 70 years. Some of the bars have been left blank on purpose.
c. Find the probability that a randomly selected runner€™s age was between 20 and 29 years, inclusive, OR between 50 and 59 years, inclusive.
d. From inspecting the density histogram, a student concludes that 5% of all Americans who run are between 10 and 19 years in age, inclusive. What would you tell the student?
e. The ages of the runners were self-reported. What type of bias likely occurred? Explain.

Transcribed Image Text:

Ages of Runners 0,04 0,03 0.02 0.01 0.26 0.30 0.16 0.18 0.0S 0.04 10 20 30 40 50 60 70 80 90 Age (years)