1.) You have collected crash data from 290 intersections that were converted from All-way stop, one/two-way stop, and signal throughout the entire state that you live in. 133 installations were new and have no pervious record. All sites were converted to roundabouts. The data was collected between the years of 2008 and 2018.

The table below represents a tally of accident types. They are seperated into groups. Each crash designation is a assigned a prefix and a group. The letters A through O describe the the crash type. A stands for Head on, B "sideswipe", C "rear end", "hit object", F "overturned" , G "Vehicle Pedestrian", and H "other" crash types. The groups are for before and after a treatment was applied. The prefix "b" stands for before and "a" stands for "after". The before group is on the left and the after group is on the right. For example, After crashes for All-Way Stop "Ba" represents 10 Sideswipes after the installation of a roundabout.

Question: You are a traffic engineer assigned to summarize the results of this before and after analysis. The data is random and sites are independent of each other. Demonstrate your ability as an engineer to summarize the data by using statistics. You may want to prove the hypothesis that the treatment was or was'nt successful. Use R to validate any assumptions for the statistical steps you may take. Use graphs to convey any messages to the reader. Thank you, your help is greatly appreciated. i hope you enjoy this problem

Background: Crashes are considered count data and they follow the negative binomial or poisson distribution. This real data .

Count of Per Sum_Ab_CT Sum_Bb_CT Sum_Cb_CT Sum_Db_CT Sum_Eb_CT Sum_Fb_CT Sum_Gb_CT Sum_Hb_CT Sum_Ob_CT Total: 47 26 45 Sum_Aa_CT Sum_Ba_CT Sum_Ca_CT Sum_Da_CT Sum_Ea_CT Sum_Fa_CT Sum_Ga_CT Sum_Ha_CT Sum_Oa_CT Total: 10 13 2 5 27 OBJECTID * Previous_Control 1 All-Way Stop 2 None (new) 3 One/Two-Way Stop 4 Signal 91 100 0 O 4 133 89 00 Bow w a un 49 23 wou 21 Now v 132 11 29 26 40 132 30 21 20 68 Count of Per Sum_Ab_CT Sum_Bb_CT Sum_Cb_CT Sum_Db_CT Sum_Eb_CT Sum_Fb_CT Sum_Gb_CT Sum_Hb_CT Sum_Ob_CT Total: 47 26 45 Sum_Aa_CT Sum_Ba_CT Sum_Ca_CT Sum_Da_CT Sum_Ea_CT Sum_Fa_CT Sum_Ga_CT Sum_Ha_CT Sum_Oa_CT Total: 10 13 2 5 27 OBJECTID * Previous_Control 1 All-Way Stop 2 None (new) 3 One/Two-Way Stop 4 Signal 91 100 0 O 4 133 89 00 Bow w a un 49 23 wou 21 Now v 132 11 29 26 40 132 30 21 20 68