Introduction to Subjective Probability Learning

A subjective probability shows a particular person’s individual judgement. That are, how likely accurate event is to happen. A subjective probability result is carrying a value range from 0 to 1.
A rare event is carrying value near to 0 as subjective probability. A frequent event is carrying value near to 1 as subjective probability. Let us see learning example problems for subjective
probability.

Example Problem 1 - Subjective Probability Learning

In a car parking area there are totally 32 cars available. In those, 3 are Innova cars, 8 are Swift cars, 15 are Accent cars and remaining are Ford cars. Compute the probability for choosing i)
Swift cars ii) Ford cars?

Solution:

Total number of cars in car parking, n(S) = 32

Number of Innova cars = 3

Number of Swift cars = 8

Number of Accent cars = 15

Number of Ford cars = 32 – (3+8+15) = 6

Let A be the event of selecting Swift cars.

So, n(A) = 8

P(A) = `(n(A))/(n(S))`

= `8/32`

= `1/4`

Let B be the event of selecting Ford cars.

So, n(B) = 6

P(B) = `(n(B))/(n(S))`

= `6/32`

= `3/16`

Example Problem 2 - Subjective Probability Learning

Compute the probability of choosing a letter ‘E’ from the word ‘NETHERLAND’?

Solution:

Given word is, “NETHERLAND”

Here, total letters, n(S) = 10

Let consider G be the event of choosing a letter ‘E’ from the given word.

Total number of letter ‘E’, n(G) = 2

So, probability of choosing letter ‘E’, P(G) = `(n(G))/(n(S))`

= `2/10`

= `1/5`

Example Problem 3 - Subjective math Probability Learning

Jessie is tossing three coins at the same time. What is the probability of Jessie getting exactly three head or exactly one tail?

Solution:

The sample space, when three fair coins tossed is,

S = {HHH, HHT, HTH, THH, HTT, THT, TTH, TTT}

n(S) = 8

A be the event of receiving exactly three head,

n(A) = {HHH} = 1

B be the event of receiving exactly one tail,

n(B) = {HHT, HTH, THH} = 3

P(A) = `(n(A))/(n(S))` = `1/8`

P(B) = `(n(B))/(n(S))` = `3/8`

P(A or B) = P(A) + P(B)

= `1/8` + `3/8`

= `4/8`

= `1/2`

= 0.5

That’s all about subjective probability learning.