Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

Why my calculation is different from R calculation A radioactive object emits pa

ID: 3333946 • Letter: W

Question

Why my calculation is different from R calculation

A radioactive object emits particles according to a Poisson process at an
average rate of 7.5 particles per second. We observe the object for a total of 5 seconds.
Suppose it is known that at least 20 particles will be emitted during this interval, what is
the probability that no more than 25 particles will be emitted during this interval?

P( X = 20 ) = e ^-37.5 * 37.5^20 / 20! = 0.0006
P( X = 21 ) = e ^-37.5 * 37.5^21 / 21! = 0.0011
P( X = 22 ) = e ^-37.5 * 37.5^22 / 22! = 0.002
P( X = 23 ) = e ^-37.5 * 37.5^23 / 23! = 0.0032
P( X = 24 ) = e ^-37.5 * 37.5^24 / 24! = 0.005
P( X = 25 ) = e ^-37.5 * 37.5^25 / 25! = 0.0075

> ppois (c (25, 20), lambda-37.5) [1] 0.02008004 0.00130784 >0.02008004-0.00130784 11] 0.0187722

Explanation / Answer

The calculations are correct , it is just the rounding of numbers that effects the final answers .

however , if you look closely rounding the answers to 3 decimal places for both the values , the answer is

0.019

0.0194 ~ 0.019

0.018772 ~ 0.019

Hire Me For All Your Tutoring Needs
Integrity-first tutoring: clear explanations, guidance, and feedback.
Drop an Email at
drjack9650@gmail.com
Chat Now And Get Quote