Probability! (1 Viewer)

[z600]

Does anyone know how to do the following Qs

An insurance company notices that of 2400 claims made for burglary only 10% of premises had alarms and 16% had keyed window locks. The number of claims where premises had both an alarm and keyed window locks was 147. If a claim is chosen at random and the premises had no alarm what is the probability that there were also no
window locks?

 

[tommykins]

Show some incentive and do some working out then people might help you.

 

[joshdavid]

what is the final answer??

cos i got some weird number =)

 

[study-freak]

Use a Venn Diagram.

 

[TehAzner]

Does anyone know how to do the following Qs

An insurance company notices that of 2400 claims made for burglary only 10% of premises had alarms and 16% had keyed window locks. The number of claims where premises had both an alarm and keyed window locks was 147. If a claim is chosen at random and the premises had no alarm what is the probability that there were also no
window locks?

My friend just asked me this question. Except in his one it had 2300 and 125 alarm and keyed window locks.

(1) Draw a Venn Diagram
(2) Read the question carefully, there's a "trick" to this question.

Other than that it's pretty easy.

 

[wrong_turn]

you mean its just 147/2400 = 0.06125?

hell, it couldnt be that easy :S

premises had no alarm what is the probability that there were also no
window locks

 

[study-freak]

you mean its just 147/2400 = 0.06125?

hell, it couldnt be that easy :S

premises had no alarm what is the probability that there were also no
window locks

No of premises with a window lock but without an alarm=237
No of premises without an alarm and a window lock=1923

P(No window lock out of the ones without an alarm)=(1923)/(237+1923)

I hope I didn't make any calculation error...

 

[midifile]

seriously, that question is worth 10% of a 1% quiz
as if youd actually care so much about 0.1% of your overall mark

and yeah, what study-freak did is correct

 

[wendus]

yeah i had a problem with that q as well. thanks study-freak! he's in year 12 and doing better than me.

 

[kent]

nice