Questions: The sum of all the probabilities in a discrete probability distribution must be equal to 1
Transcript text: Part 2 of 2
The sum of all the probabilities in a discrete probability distribution must be equal to $\square$
Solution
Solution Steps
To solve this problem, we need to understand that in a discrete probability distribution, the sum of all individual probabilities must equal 1. This is a fundamental property of probability distributions.
Step 1: Define the Probabilities
We are given a discrete probability distribution with the following probabilities:
\[
P_1 = 0.2, \quad P_2 = 0.3, \quad P_3 = 0.1, \quad P_4 = 0.4
\]
Step 2: Calculate the Sum of Probabilities
We calculate the sum of all probabilities:
\[
\text{Sum} = P_1 + P_2 + P_3 + P_4 = 0.2 + 0.3 + 0.1 + 0.4 = 1.0
\]
Step 3: Validate the Probability Distribution
According to the properties of probability distributions, the sum of all probabilities must equal \(1\):
\[
\text{Sum} = 1.0
\]
Since the calculated sum is equal to \(1\), the distribution is valid.
Final Answer
The sum of all the probabilities in a discrete probability distribution must be \( \boxed{1} \).