In a study of the feasibility of a red-light camera program in the city of

Milwaukee, the data above summarize the projected number of crashes at 13 selected intersections over a 5-year period.
(a) Identify the variables presented in the table.
(b) State whether each variable is qualitative or quantitative. If quantitative, state whether it is discrete or continuous.
(c) Construct a relative frequency distribution for each system.
(d) Construct a side-by-side relative frequency bar graph for the data.
(e) Determine the mean number of crashes per intersection in the study, if possible. If not possible, explain why.
(f) Determine the standard deviation number of crashes, if possible. If not possible, explain why.
(g) Based on the data shown, does it appear that the red-light camera program will be beneficial in reducing crashes at the intersections? Explain.
(h) For the current system, what is the probability that a crash selected at random will have reported injuries?
(i) For the camera system, what is the probability that a crash selected at random will have only property damage?
The study classified crashes further by indicating whether they were red-light running crashes or rear-end crashes. The results are as follows:

(j) Using Simpson’s Paradox, explain how the additional classification affects your response to part (g).
(k) What recommendation would you make to the city council regarding the implementation of the red-light camera program? Would you need any additional information before making your recommendation? Explain.

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Crash Type Reported injury Reported property damage only Unreported injury Unreported property damage only Total Current Systemm 289 392 With Red-Light Cameras 221 78 60 362 308 1121 922 Red-Light Running Current Cameras Current Cameras Rear End Crash Type Reported injury Reported property damage only Unreported injury Unreported property damage only Total 67 144 157 180 235 153 18 21 60 39 145 167 217 141 387 445 734 477