The recent school question and answer enquired students to say what they agree to is the main important challenge for a student to do in order for you to gain success. Of many results, the one which that stood out was practice. Persons who surely are successful do not become successful by being born. They work hard and determination their lives to succeeding. This is how you can reach your goals. following are one of the answer and question example that you can potentially utilise to practice and develop your information and also give you insights that could just help you to keep up your study in school.
Question:
8) At the school carnival, Mike will play a game in which he will toss a penny, a nickel, and a dime at the same time. He will be awarded 3 points for each coin that lands with heads faceup. Let the random variable x represent the total number of points awarded on any toss of the coins. What is the expected value of x?
Answer:
The expected value of X representing the average of the total number of points awarded on toss of the coins is 27/8
How to find the mean (expectation) of a random variable?
Supposing that the considered random variable is discrete, we get:
where is its n data values
and is the probability of
How to calculate the probability of an event?
Suppose that there are finite elementary events in the sample space of the considered experiment, and all are equally likely.
Then, suppose we want to find the probability of an event E.
Then, its probability is given as
where favorable cases are those elementary events who belong to E, and total cases are the size of the sample space.
For this case, we’re given that:
- 3 coins tossed, and its 3 points on each head outcome
- X = total number of points awarded
Now, X can have total 4 values, viz 0, 1, 2, and 3
Their each’s probability is evaluated as:
- Case 1: No heads
That means all 3 coins needs to land on tail.
There is, therefore, single way to do so. Whereas, total outcomes possible are (by product rule, as there are 2 outcomes possible for each coin)
Thus, we get:
- Case 2: Single head
When single head, that means 3 points, or X = 3
Total outcomes possible = 8,
Single head can occur in 3 different ways, as other two needs to be strictly tails.
Thus,
- Case 3: Two heads
Two heads means 3+3 = 6 points, or X = 6
Total outcomes possible = 8
Two heads means single tail. Single tail can occur in 3 different ways.
Therefore,
- Case 4: Three heads
Three heads means 3+3+3 = 9 points, or X = 9
Total outcomes possible = 8
Three heads means no tail, only single way to do it.
Thus,
Therefore, the expectation of X is calculated as:
Thus, the expected value of X is 27/8.
Learn more about expectation here:
From the answer and question examples above, hopefully, they might be able to assist the student sort out the question they had been looking for and observe of all the things declared in the answer above. You could actually then have a discussion with your classmate and continue the school learning by studying the problem as a group.