Homicide rate (homicides per 100,000 population) for each of the 50 states appeared in the 2010 Statistical Abstract (www.census.gov). A frequency distribution constructed from the 50 observations is shown in the following table:

Homicide Rate Frequency 0 to ,30 14 3 to ,60 18 6 to ,90 16 9 to ,12 1 12 to ,15 1

a. Calculate the relative frequency and density for each of the seven intervals in the frequency distribution.

Use the computed densities to construct a density histogram for the variable x 5 homicide rate for the population consisting of the 50 states.

b. Is the population distribution symmetric or skewed?

c. Use the population distribution to determine the following probabilities.

i. P(x $ 12) ii. P(x , 9) iii. P(6 # x , 12)