help please( P1 Exam)

[Dansanon]

how does one find the 90th percentile of the standard normal distribution. when I look on the table I see that It corresponds to 1.28 but the book has 1.282 how did they come up with that?

[Colonel Smoothie]

Originally Posted by Dansanon

how does one find the 90th percentile of the standard normal distribution. when I look on the table I see that It corresponds to 1.28 but the book has 1.282 how did they come up with that?

It's close enough.

[daaaave]

Some tables (although not the one given on the 1/P syllabus page) have inverse values for certain percentiles listed on the bottom. The solutions to the 1/P practice problems often use linear interpolation, which will also give you 1.282. But actual exam questions are written so that you can either round or use interpolation and not get the wrong answer choice, so 1.28 is, as was previously suggested, close enough.

[Dansanon]

Thank you but besides interpolation is there a quick way to come up with it?

[Actuarialsuck]

Originally Posted by Dansanon

Thank you but besides interpolation is there a quick way to come up with it?

Of course! Integrate! ...oh you said quick.