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

Consider three elements {e1; e2; e3} put intorandom order as in the table below.

ID: 2952187 • Letter: C

Question

Consider three elements {e1; e2; e3} put intorandom order as in the table below.

list             ¦e1e2e3 ¦e1e3e2 ¦e2e1e3 ¦e2e3e1¦e3e1e2¦ e3e2e1
________________________________________________________
probability ¦     1/2  ¦    1/4  ¦   1/8   ¦   1/16  ¦   1/32¦ 1/32

Calculate the following quantities:

(a) P(e3 precedes e2); (b) P(e2 is in position 2); (c) E( positionof e1)
Consider three elements {e1; e2; e3} put intorandom order as in the table below.

list             ¦e1e2e3 ¦e1e3e2 ¦e2e1e3 ¦e2e3e1¦e3e1e2¦ e3e2e1
________________________________________________________
probability ¦     1/2  ¦    1/4  ¦   1/8   ¦   1/16  ¦   1/32¦ 1/32

Calculate the following quantities:

(a) P(e3 precedes e2); (b) P(e2 is in position 2); (c) E( positionof e1)
Consider three elements {e1; e2; e3} put intorandom order as in the table below.

list             ¦e1e2e3 ¦e1e3e2 ¦e2e1e3 ¦e2e3e1¦e3e1e2¦ e3e2e1
________________________________________________________
probability ¦     1/2  ¦    1/4  ¦   1/8   ¦   1/16  ¦   1/32¦ 1/32

Calculate the following quantities:

(a) P(e3 precedes e2); (b) P(e2 is in position 2); (c) E( positionof e1)

Explanation / Answer

(a) P(e3 precedes e2) We can see from the table that e3 precedes e2 in  (e1e3e2), (e3e1e2), and (e3e2e1) which have the respectiveprobabilities of (1/4), (1/32), and (1/32). hence P(e3 precedes e2)= P(e1e3e2)+P(e3e1e2)+P(e3e2e1) =(1/4)+(1/32)+(1/32) = (5/16) = .3125 (b) P(e2 is in position 2) We can see from the table that e2 is in position 2 in (e1e2e3) and(e3e2e1) which have the respective probabilities (1/2) and(1/32). so, P(e2 is in position 2) = P(e1e2e3)+P(e3e2e1) =(1/2)+(1/32) = (17/32) = .53125 (c) E(position of e1)         e1 in 1stposition                               e1 in 2nd position    e1in 3rd position P       (1/2)+(1/4)=3/4                              (1/8)+(1/32)=5/32                            (1/16)+(1/32) =3/32