Math Problem Statement
An ordinary (fair) coin is tossed 3 times. Outcomes are thus triples of "heads" (h) and "tails" (t) which we write hth, ttt, etc.
For each outcome, let N be the random variable counting the number of tails in each outcome. For example, if the outcome is hth, then N (hth) = 1. Suppose that the random variable X is defined in terms of N as follows: X = N2-3N-3. The values of X are given in the table below.
Outcome
tth
thh
hht
tht hhh
itt
het hth
Value of
X-5-5-5-5-3-3-5-5
Calculate the probabilities P(X= x) of the probability distribution of X. First, fill in the first row with the values of X. Then fill in the appropriate probabilities in the second row.
Value x of X
미
P(X=x)
X
5
Solution
To solve this problem, let's break it down step by step.
Step 1: Understand the Random Variable
The random variable is defined in terms of , which is the number of tails in a particular outcome. The function defining is given by:
Step 2: Determine for Each Outcome
List the possible outcomes when a fair coin is tossed 3 times. There are possible outcomes:
- (0 tails)
- (1 tail)
- (1 tail)
- (1 tail)
- (2 tails)
- (2 tails)
- (2 tails)
- (3 tails)
For each outcome, count the number of tails and calculate using the formula .
Step 3: Calculate the Values of
Now, calculate for each possible value of :
- :
- :
- :
- :
Step 4: Assign Values to Each Outcome
Using the outcomes listed above, assign the calculated values:
- (0 tails):
- (1 tail):
- (1 tail):
- (1 tail):
- (2 tails):
- (2 tails):
- (2 tails):
- (3 tails):
Step 5: Calculate the Probability Distribution
Now, determine the probability of each value of occurring.
- occurs in 2 outcomes: and .
- occurs in 6 outcomes: , , , , , and .
Since each outcome is equally likely with probability :
Final Answer
The probability distribution of is as follows:
X & -5 & -3 \\ \hline P(X = x) & \frac{3}{4} & \frac{1}{4} \\ \end{array}$$ Would you like more detailed steps or explanations about this problem? Here are some related questions: 1. How do you compute the expected value of $$X$$ based on this probability distribution? 2. What is the variance of $$X$$ in this scenario? 3. How do you interpret the random variable $$X$$ in this context? 4. How does the binomial distribution relate to this problem? 5. How would the distribution change if the coin was biased? 6. Can you explain the concept of conditional probability using this example? 7. What is the significance of the function $$X = N^2 - 3N - 3$$? 8. How do these results change if the number of coin tosses is increased? **Tip**: When working with probability distributions, always ensure that the sum of the probabilities equals 1 as a check for your calculations.Ask a new question for Free
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Math Problem Analysis
Mathematical Concepts
Probability Theory
Random Variables
Expected Value
Formulas
X = N^2 - 3N - 3
Theorems
-
Suitable Grade Level
College Level
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