# What is the expected value for the sum of 100 fair dice rolls?

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## How do you find the expected value of dice rolls?

The expected value of the random variable is (in some sense) its average value. You compute it by multiplying each value x of the random variable by the probability P(X=x), and then adding up the results. So the average sum of dice is: E(X) = 2 . 1/36 + 3 . 2/36 + ….

## What is the expected number of rolls to get a 6?

If you then take the expectation of that probability ( in other words how many times you expect to roll the die before you get a 6) is 1/p where p is the probability of rolling a 6. The probability of rolling a 6 will always be 1/6 since the experiment is independent. So the expected number of rolls will be 1/1/6=6.

## How do you find the expected value of the sum?

The expected value of the sum of several random variables is equal to the sum of their expectations, e.g., E[X+Y] = E[X]+ E[Y] . On the other hand, the expected value of the product of two random variables is not necessarily the product of the expected values.

## How do you calculate the expected value?

In statistics and probability analysis, the expected value is calculated by multiplying each of the possible outcomes by the likelihood each outcome will occur and then summing all of those values. By calculating expected values, investors can choose the scenario most likely to give the desired outcome.

## How do you find the expected value of a normal distribution?

The expected value µ = E(X) is a measure of location or central tendency. The standard deviation σ is a measure of the spread or scale. The variance σ2 = Var(X) is the square of the standard deviation. To move from discrete to continuous, we will simply replace the sums in the formulas by integrals.

## What is the expected value of the sum of two dice?

The expectation of the sum of two (independent) dice is the sum of expectations of each die, which is 3.5 + 3.5 = 7. Similarly, for N dice throws, the expectation of the sum should be N * 3.5. If you’re taking only the maximum value of the two dice throws, then your answer 4.47 is correct.

## How do you get 6 dice?

Just type /roll (or the shorter /r) command into the q Text Chat box, followed by a formula. Roll D20, D100, D8, D10, D12, D4, and more. One way to cheat is to play with loaded dice, which are altered so that a particular side will land face up more often than normal. A die has 6 sides: 1, 2, 3, 4, 5, and 6.

## What is the expectation of getting 5 on a roll of a dice?

Two (6-sided) dice roll probability table

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Roll a… Probability
4 3/36 (8.333%)
5 4/36 (11.111%)
6 5/36 (13.889%)
7 6/36 (16.667%)

## What is the probability of rolling a six in two rolls in a row?

The probability of rolling two sixes on two rolls is 16 as likely as one six in one roll.

## How do you find the expected value of a table?

To find the expected value, E(X), or mean μ of a discrete random variable X, simply multiply each value of the random variable by its probability and add the products. The formula is given as. E ( X ) = μ = ∑ x P ( x ) .

## What is expected value of a random variable?

The expected value of a random variable is denoted by E[X]. The expected value can be thought of as the “average” value attained by the random variable; in fact, the expected value of a random variable is also called its mean, in which case we use the notation µX.