Constructing the Sample Space

Oct 13, 2025 by wbrum.org 32 views

Introduction

In probability theory, a sample space is a set of all possible outcomes of an experiment. In this article, we will explore the concept of a sample space and its application to a computer-generated sequence of three digits. We will also calculate the probability of a sequence containing exactly one 0.

Constructing the Sample Space

A computer is programmed to generate a sequence of three digits, where each digit is equally likely to occur. This means that each digit can take on any value from 0 to 9, inclusive. To construct the sample space, we need to list all possible sequences of three digits.

S = {000, 001, 002, 003, 004, 005, 006, 007, 008, 009,
     010, 011, 012, 013, 014, 015, 016, 017, 018, 019,
     020, 021, 022, 023, 024, 025, 026, 027, 028, 029,
     030, 031, 032, 033, 034, 035, 036, 037, 038, 039,
     040, 041, 042, 043, 044, 045, 046, 047, 048, 049,
     050, 051, 052, 053, 054, 055, 056, 057, 058, 059,
     060, 061, 062, 063, 064, 065, 066, 067, 068, 069,
     070, 071, 072, 073, 074, 075, 076, 077, 078, 079,
     080, 081, 082, 083, 084, 085, 086, 087, 088, 089,
     090, 091, 092, 093, 094, 095, 096, 097, 098, 099}

The sample space S contains 1000 possible sequences of three digits.

Calculating the Probability

We want to calculate the probability that a sequence will contain exactly one 0. To do this, we need to count the number of sequences that satisfy this condition and divide it by the total number of sequences in the sample space.

Let's count the number of sequences that contain exactly one 0. We can do this by considering the following cases:

The sequence contains a 0 in the first position: There are 9 possible choices for the second digit (1-9) and 9 possible choices for the third digit (0-9). This gives us a total of 9 × 9 = 81 sequences.
The sequence contains a 0 in the second position: There are 9 possible choices for the first digit (1-9) and 9 possible choices for the third digit (0-9). This gives us a total of 9 × 9 = 81 sequences.
The sequence contains a 0 in the third position: There are 9 possible choices for the first digit (1-9) and 9 possible choices for the second digit (0-9). This gives us a total of 9 × 9 = 81 sequences.

In total, there are 81 + 81 + 81 = 243 sequences that contain exactly one 0.

Probability Calculation

The probability of a sequence containing exactly one 0 is given by the formula:

P(exactly one 0) = (Number of sequences with exactly one 0) / (Total number of sequences)

Substituting the values, we get:

P(exactly one 0) = 243 / 1000 = 0.243

Therefore, the probability that a sequence will contain exactly one 0 is 0.243 or 24.3%.

Conclusion

In this article, we constructed a sample space that shows all possible sequences of three digits generated by a computer. We then calculated the probability of a sequence containing exactly one 0. The probability was found to be 0.243 or 24.3%. This example illustrates the importance of understanding sample spaces and calculating probabilities in probability theory.

References

[1] Introduction to Probability Theory by Grinstead and Snell
[2] Probability and Statistics by DeGroot and Schervish

Introduction

In our previous article, we explored the concept of a sample space and its application to a computer-generated sequence of three digits. We also calculated the probability of a sequence containing exactly one 0. In this article, we will answer some frequently asked questions related to this topic.

Q&A

Q: What is a sample space?

A: A sample space is a set of all possible outcomes of an experiment. In the context of a computer-generated sequence of three digits, the sample space S contains all possible sequences of three digits.

Q: How do we construct a sample space?

A: To construct a sample space, we need to list all possible outcomes of an experiment. In the case of a computer-generated sequence of three digits, we can list all possible sequences of three digits, where each digit can take on any value from 0 to 9, inclusive.

Q: What is the probability of a sequence containing exactly one 0?

A: We calculated the probability of a sequence containing exactly one 0 to be 0.243 or 24.3%. This means that out of all possible sequences of three digits, 24.3% of them will contain exactly one 0.

Q: How do we calculate the probability of a sequence containing exactly one 0?

A: To calculate the probability of a sequence containing exactly one 0, we need to count the number of sequences that satisfy this condition and divide it by the total number of sequences in the sample space. We can do this by considering the following cases:

The sequence contains a 0 in the first position: There are 9 possible choices for the second digit (1-9) and 9 possible choices for the third digit (0-9). This gives us a total of 9 × 9 = 81 sequences.
The sequence contains a 0 in the second position: There are 9 possible choices for the first digit (1-9) and 9 possible choices for the third digit (0-9). This gives us a total of 9 × 9 = 81 sequences.
The sequence contains a 0 in the third position: There are 9 possible choices for the first digit (1-9) and 9 possible choices for the second digit (0-9). This gives us a total of 9 × 9 = 81 sequences.

In total, there are 81 + 81 + 81 = 243 sequences that contain exactly one 0.

Q: What is the total number of sequences in the sample space?

A: The total number of sequences in the sample space is 1000, since each digit can take on any value from 0 to 9, inclusive.

Q: How do we calculate the probability of a sequence containing exactly one 0 using the formula?

A: The probability of a sequence containing exactly one 0 is given by the formula: