Question

(a) among total crashes in other weather conditions, what is the probability that a randomly - selected fatal crash occurs when it is dark (without light)? the probability that a randomly selected fatal crash in other weather conditions occurs when it is dark (without light) is approximately 0.491 (round to three decimal places as needed.) (b) among fatal crashes when it is dark (without light), what is the probability that a randomly selected fatal crash occurs in other weather conditions? the probability that a randomly selected fatal crash when it is dark (without light) occurs in other weather conditions is approximately . (round to three decimal places as needed.) data table
weather light conditions
daylight dark, but lighted dark dawn/dusk other
normal 14307 5875 8151 1183 65
rain 875 497 681 87 8
snow/sleet 219 51 156 17 2
other 125 54 220 40 9
unknown 810 255 548 71 133

Explanation:

Step1: Calculate total fatal crashes when it is dark (without light)

Sum up the "Dark" column values for all weather conditions: $8151 + 681+156 + 220+548=9756$

Step2: Calculate total fatal crashes in other weather conditions when it is dark (without light)

From the "Other" row and "Dark" column, the value is $220$

Step3: Calculate the probability

The probability $P=\frac{220}{9756}\approx 0.023$

Answer:

$0.023$