Instructions for The Cab Problem


A cab was involved in a hit-and-run accident at night. There are two cab companies in the city, the Blue and Green. Your task is to judge (or estimate) the probability that the cab in the accident was a Blue cab.

You will be given information about the percentage of accidents at night that were caused by Blue cabs, and the testimony of a witness who saw the accident.

The percentage of night-time accidents involving Blue cabs is based on the previous 2 years in the city. In different cities, this percentage was either 15%, 30%, 70%, or 85%. The rest of night-time accidents involved Green cabs.

Witnesses were tested for their ability to identify colors at night. The witnesses were presented 100 Blue and 100 Green cabs to identify at night.

The MEDIUM witness correctly identified 60% of the cabs of each color, calling Green cabs "Blue" 40% of the time and calling Blue cabs "Green" 40% of the time.

The HIGH witness correctly identified 80% of each color, calling Blue cabs "Green" or Green cabs "Blue" on 20% of the tests.

In summary, you will be given information about the rate at which Blue cabs are involved in accidents at night, and you will be given the testimony of a witness. The witness was either "high" in accuracy (80% correct) or "medium" in accuracy (60% correct). In some cases, there was no witness. Your task is to estimate the probability that the cab in the particular accident was actually a Blue cab in each case. Express your judgment of probability as a percentage (i.e., 0 to 100). Do NOT type the percent sign.

Warmup Trials for the Cab Problem


W1. 15% of accidents are Blue Cabs & high witness says "Green".
W2. 85% of accidents are Blue Cabs & high witness says "Blue".
W3. 15% of accidents are Blue Cabs & high witness says "Blue".
W4. 70% of accidents are Blue Cabs & there was no witness.
W5. 85% of accidents are Blue Cabs & high witness says "Green".
W6. 30% of accidents are Blue Cabs & medium witness says "Green".
W7. 85% of accidents are Blue Cabs & medium witness says "Blue".

Please re-read the instructions, check your warmups, and then proceed to the trials below.


1. 85% of accidents are Blue Cabs & medium witness says "Green".
2. 15% of accidents are Blue Cabs & medium witness says "Blue".
3. 15% of accidents are Blue Cabs & medium witness says "Green".
4. 15% of accidents are Blue Cabs & there was no witness.
5. 30% of accidents are Blue Cabs & high witness says "Blue".
6. 15% of accidents are Blue Cabs & high witness says "Green".
7. 70% of accidents are Blue Cabs & there was no witness.
8. 15% of accidents are Blue Cabs & high witness says "Blue".
9. 70% of accidents are Blue Cabs & high witness says "Blue".
10. 85% of accidents are Blue Cabs & high witness says "Green".
11. 70% of accidents are Blue Cabs & high witness says "Green".
12. 85% of accidents are Blue Cabs & medium witness says "Blue".
13. 30% of accidents are Blue Cabs & medium witness says "Blue".
14. 30% of accidents are Blue Cabs & high witness says "Green".
15. 70% of accidents are Blue Cabs & medium witness says "Blue".
16. 30% of accidents are Blue Cabs & there was no witness.
17. 30% of accidents are Blue Cabs & medium witness says "Green".
18. 70% of accidents are Blue Cabs & medium witness says "Green".
19. 85% of accidents are Blue Cabs & high witness says "Blue".
20. 85% of accidents are Blue Cabs & there was no witness.

21. What is your age? years.
22. Gender: Are you Male or Female?
Female
Male

23. How many years of Education have you completed? Put 12 for High School Diploma
Put 16 for college diploma (bachelor's degree).
put 20 for doctorate degree (Ph.D., M.D., etc).
Education:
24. Nationality (country of birth):
25. Comments:

Please check your answers. When you are done, push the button below.

Thank You!