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Probability
The probability of a certain event is a number expressing the likelihood that a specific event will occur, expressed as the ratio of the number of actual occurrences to the number of possible occurrences. In mathematics, it is a measure of how often an event will happen and is the basis of statistics.
14,643 Questions
What is the probability that a male offspring will have hemophilia?
Without any further information, the probability is between 0.0001 and 0.0002
What are the odds against rolling a 4 in a fair die?
Well I'm supposing it's a 6 sided dye. Since there are 6 sides it's a 1 out of 6 chance or 16% chance that you would roll a 4.
The odds against rolling a 4, the complementary event, are 5 out of 6, a chance
of: 1 - 0.1666.. = 0.8333... ≈ 83.3%.
What is the probability of having exactly 2 boys out of 6 children?
The answer depends on whether the children are picked at random. If they were selected from inside a girls' school the probability should be quite close to 0. Likewise, if the children were picked inside a boys' school.
If six children are picked at random from a large group of children with an equal number of boys and girls, then the answer is
6C2*(1/2)6 = 15/32 = 0.47, approx.
How do you solve for probabilities in binomial distributions?
Suppose you have n trials of an experiment in which the probability of "success" in each trial is p. Then the probability of r successes is:
nCr*pr*(1-p)n-r for r = 0, 1, ... n.
nCr = n!/[r!*(n-r)!]
What is marginal probability function?
If f(x, y) is the joint probability distribution function of two random variables, X and Y, then the sum (or integral) of f(x, y) over all possible values of y is the marginal probability function of x.
The definition can be extended analogously to joint and marginal distribution functions of more than 2 variables.
5 marbles. 3 red marbles, 2 white marbles.
The probability of drawing a white marble is P(W) = 2/5 = 0.40
If the white marble is not returned to the rest of the marbles (no substitution), the
probability that the second marble drawn is a red one is P(R) = 3/4 = 0.75.
The probability that the event of drawing first a white marble and without substitution
the second draw turns a red marble is P(1stW,2ndR) = (2/5)∙(3/4) = 6/20 = 3/10 = 0.30 = 30.0%.
If the process of drawing the marbles is with substitution, the probability of the
second draw turning a red marble is P(R) = 3/5 = 0.60 = 60.0%
The probability that the event of first drawing a white marble and after returning the
marble back to the original group of marbles (with substitution) the second draw turns a red marble is P(1stW,2ndR) = (2/5)∙(3/5) = 6/25 = 0.24 = 24.0%.
If there are 48 tacks, (15+5+20+8), you want to divide the number of one color over the total to find the percentage of that color out of the whole.
If there are 8 silver tacks, take 8 over 48, which equals .167.If there are 20 white tacks, take 20 over 48, which equals .4167
Now you know the percentage of silver out of the whole, and the percentage of white out of the whole.
To figure out the white and silver together, add them together!
White and Silver tacks make up about .583, or 58.3%
And that's your answer. You have a 58% chance of picking a white or silver tack from the box when picked at random.
No. There are 24 hours in a day, not 12!
Should the numbers for the experimental probability be close to the theoretical probability?
Not necessarily. There may not even be a way to work out a theoretical probability. Furthermore, there is always a chance, however small, that the experimental probability is way off.
What is the likelihood a certain event will occur?
Its probability. The probability for a certainty is 1.
What is multiplication rule in probability?
Given two events, A and B, the conditional probability rule states that
P(A and B) = P(A given that B has occurred)*P(B)
If A and B are independent, then the occurrence (or not) of B makes no difference to the probability of A happening. So that
P(A given that B has occurred) = P(A)
and therefore, you get
P(A and B) = P(A)*P(B)
What is the probability of rolling a 6 sided dice and getting a factor of 20?
The factors of 20 on a die are: 1,2,4,5
Therefore it is a 4 out of 6 chance you will roll one of the factors. In simplest form, a 2 out of 3 chance or 66 2/3 chance.
What is the sample variance and the estimated standard error for a sample of n 4 scores with SS 300?
The sample variance is obtained by dividing SS by the degrees of freedom (n-1). In this case, the sample variance is
SS/(n-1) = 300/(4-1) = 300/3 = 100
In order to get the standard error, you can do one of two things:
a) divide the variance by n and get the square root of the result:
square.root (100/4) = square.root(25) = 5, or
b) get the standard deviation and divide it by the square root of n.
10/square.root(4) = 10/2 = 5
What is the probability of rolling a number less than 5 AND an odd number on one die?
The answer depends on how many times the one die is rolled!
In just one roll, the answer is 1/3.
When two number cubes are rolled what is the probability that their sum will be 3?
On a roll of two dice, the chance of rolling a 3 (one and two) is 2 in 36, or 1 in 18 when reduced.
What percent of the scores in a normal distribution will fall within one standard deviation?
It is 68.3%
How would you characterize the distribution of scores in a normal distribution?
They are said to be Normally distributed.
How many five-card hands are possible in a 52 card deck This is probability?
There are 2,598,960 5-card hands.
This is combinatorials, which is used in probability but is not probability itself.
When a coin is tossed 10 times what is the probability of getting exactly six head?
Assuming it is a fair coin, P(6H in 10 tosses) = 10C6 * (1/2)6*(1/2)(10-6) = [10*9*8*7/(4*3*2*1)]/210
=210/1024 = 0.2051
What is the probability of selecting a car with a manual transmission?
The basic information required is the number of manual and automatic transmission cars that are in the region in which the selection is made. This will vary according to the region. Since that information is not available, it is not possible to give a useful answer to the question.
What is the probability of the coin landing heads up twice and tails up one?
What is the chance of it landing on heads twice in a row?
