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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 of picking a Jack Queen or King from a pack of cards?
> 1/13
Actually, there are 12 face cards in a deck, so the probability is 12/52 = 3/13 = 0.231
What is the probability of drawing either three red cards or three face cards if you choose three?
Red cards will be a 1/3 chance to pick out of three cards .
What is 0.120 kg equal to in grams?
1 Gram = 0.01kg. 1 gram*12 = 12 grams (0.01kg * 12 = 0.12kg (0.120kg)). So 12 grams.
Who uses empirical probability?
Help! I have no clue what profession uses empirical probability.
Linda in Nevada
What is the probability of not getting a 2 on two dice?
Number of possibilities with one cube = 6
Number of possibilities with two cubes = 6 x 6 = 36
Number of ways to roll a 2: Only one way: 1 ... 1
Number of ways not to roll a two = 35 ways.
Probability of not rolling a 2 = 35/36 = 97.2%(rounded)
no
How many distinguishable permutations of letters are possible in the word critics?
The word critics has 7 letters which can be arranged in 7! = 7 * 6 * 5 * 4 * 3 * 2 * 1 ways. To see this, imagine placing one of the 7 letters in the first slot. Then place a different letter in the second slot (there are only 6 letters left now), then 5 and so on down to 1. We multiply because we must do each of these steps to create a rearrangement of the word critics.
The problem then is that critics contains 2 'c's and 2 'i's, which are indistinguishable. For example, we might count "rtiicsc" several times by switching the places of the 'i's or the 'c's even though we cannot tell the difference in the word. So, we must divide out the repetition, by dividing by 2! = 2 * 1 twice. This corrects the over-counting from the duplicate letters.
So the correct result is 7!/(2! * 2!) = 1260 distinguishable permutations.
To get a seven on either roll, you would have a one in six chance. That's because no matter what value one of your dice is, there will always be one other value that the other one can be in order to add up to seven.
Your chance of rolling two in a row then would be (1/6)2, or 1/36.
Assuming 6 sided dice, each die could roll 1-6, so:
X| 1 2 3 4 5 6
1| 2 3 4 5 6 7
2| 3 4 5 6 7 8
3| 4 5 6 7 8 9
4| 5 6 7 8 9 10
5| 6 7 8 910 11
6| 7 8 9 101112
These are all the possible outcomes of a roll of 2 dice. We see that there are 6 rolls that give us 7, so we have 6/36, or 1/6. That means that we have a 1/6 chance for a 7 each roll. Then, if we have a 1/6 chance for each in a row, we have 1/6*1/6, or 1/36 chance of rolling two 7's.
Why sample is chosen instead of testing the entire population?
Sometimes, there are too much of the thing you are testing, so it is a lot easier to just take a sample.
For example, if there were twelve million weeds growing on a field and you wanted to see how many of them were dandelions, it would take forever to count all the dandelions on that field. It is more practical just to take a small sample.
What is the sum of the probabilities of all possible outcomes?
The sum of the probabilities of all possible outcomes is 1.
What is probability sampling and non probability sampling?
In probability sampling,every item in the population has a known chance of being selected as a member.In non-probability sampling, the probability that any item in the population will be selected for a sample cannot be determined.
random.
What would be the experimental probability of rolling a die 50 times and getting 4?
The experimental probability can't be predicted. If it could, then there wouldn't be
any reason to do experiments.
The probability of rolling a die 50 times depends on how passionately you want to
see what's going to happen if you do.
There are six different ways a single die can come up on each roll. So the probability of
rolling any particular number between 1 and 6 on each roll is 1/6 or (16 and 2/3) percent.
If it isn't, then the die isn't a fair die.
The die has no memory, so the probability of any particular number is the same on every roll,
even if the same number has or hasn't come up on the previous 100 or 1,000 consecutive
rolls. If the probability of any outcome depends on what has come before, then the laws
of probability aren't operating, and it's not an honest game.
The possibility is favorable. Now we'll go ahead and calculate the probability,
which is the thing you actually need to know when you're standing at the table
and it's your roll:
The die can come up in 6 ways on each roll. That's 36 different possibilities on 2 rolls.
Number of ways to make greater than 9 on the 2 rolls = 4 .
5, 5
5, 6
6, 5
6, 6
Probability of more than 9 on 2 rolls = 4/36 = 1/9= (11 and 1/9) percent .
relative frequency method
How do you subtract standard deviations?
Square the standard deviations, subtract/add them and calculate the square root of the subtraction/sum.
StDV=sqrt (StDvA^2+StDvB^2)
Does standard deviation have to be between 0 and 1?
Standard deviation doesn't have to be between 0 and 1.
What does the expected value of a binomial distribution with n trials tell you?
average number of successes
99.7% of scores fall within -3 and plus 3 standard deviations around the mean in a normal distribution.
What is a single peaked distribution in statistics?
The classic example is a Bell curve. IQ testing (using the WAIS, or Wechsler Adult Intelligence Scale) yields a peak at the 100-105 IQ mark, with a downward curve on either side of the peak - representing the higher and lower IQ scores, respectively.
1 in 15 chances that the marble will be blue, because there are 15 marbles all together in a bag, and you are only picking one out of it.
