0
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
When a standard windsock becomes fully inflated the windspeed equals or exceeds?
A fully extended standard windsock, per FAA standards, means the wind is at least 15 knots or 17 MPH.
What are the odds of rolling two dice and getting snake eyes twice in a row?
Possible results when rolling the first cube = 6
Possible results when rolling the second cube = 6
Possible results when rolling two cubes = 6 x 6 = 36
How many of these 36 possibilities are snake-eyes ? Only 1 .
Probability of snake-eyes on the first roll = 1/36
Probability of snake-eyes on the second roll = 1/36
Probability of snake-eyes on both rolls = 1/36 x 1/36 = 1/1,296 = 0.077 percent
Odds = (1 in 1,296) or (1,295 to 1) against it.
The probability of an outcome that is unwanted occuring is called?
The probability of failure.
Actually, the phrases used have very confusing connotations. When studying the risk of people being killed by lightning strikes, a "success" or the "desired outcome" is death caused by lightning. I somehow doubt that the person struck would consider it a desired outcome or a success!
How many eyes are there on the back of a deck of cards?
There need not be any. Most decks of cards have backs that are geometric patterns, not eyes.
What does probability of an event mean?
Probability is the likelihood, expressed in numerical or ratiometric terms, that an event will occur. A probability of 1 means that the event will occur. A probability of 0 means that the event will not occur. A probability of 0.5 means that the likelihood of the event occurring is equal to the likelihood of it not occurring. For instance, a fair coin has a 0.5 probability of being heads, and a 0.5 probability of being tails.
Defined formally, probability is the number of permutations of the desired outcome divided by the number of permutations of all possible outcomes. Take a standard six-sided die, for instance. There are six permutations. One of them is a 1, so the probability of rolling a 1 is 1 in 6, or about 0.1667.
Probability is not assured. If you roll a die 600 times, you will not necessarily get 100 1's. Over the long run, you will approach that outcome, but each trial will have different results. This is the difference between theoretical probability and experimental probability - theoretical being the mathematical estimate - experimental being the observed results.
What is the probability of drawing two diamonds in two draws without replacing?
The probability of drawing a diamond from a standard 52-card poker deck without jokers is 13/52, or 1/4.
The probability of drawing a second diamond at that point would then be 12/51, for an overall probability of 12/212, or 3/53. This amounts to about a 5.88% chance.
What is the probability of drawing at least one spade in two draws without replacing?
It is approx 0.44
What is the probability of you getting a 4 of diamonds?
The probability of pulling a four of diamonds from a standard deck of playing cards with the jokers removed is 1:52, the same as pulling any other individual card from the deck.
How do you create data set with larger standard deviation?
Standard deviation is the square root of the sum of the squares of the deviations of each item from the mean, i.e. the square root of the variance. In order to increase the standard deviation, therefore, you need to increase the average deviation from the mean.
There are many ways to do this. One is to move each item further away from the mean. For example, take the set [2, 4, 4, 4, 5, 5, 7, 9]. It has a mean of 5 and a standard deviation of 2.14. Multiply each item by 2.2 and subtract 5, giving the set [-1.3, 2.9, 2.9, 2.9, 5, 5, 9.2, 13.4], effectively moving each item 10% further away from the mean. This still has a mean of 5, but the standard deviation is 4.49.
What does the higher standard deviation data set explain?
A higher standard deviation means that the data are fluctuating more widely with respect to the mean. It could mean there are some bad samples, or it could simply mean that the data are not as tightly bound to the mean as anticipated. An unexpected standard deviation should be evaluated, using more robust analyses techniques, so as to differentiate between the various explanations. This is an expected part of error analysis, without which an analysis is incomplete.
9
What is the chance of winning twice when the odds are 50 percent?
If you mean like a coin toss, it's 50% probability of winning, also known as even or 1:1 odds.
Winning once has a probability of p=0.5. Winning twice has a probability of p*p = p^2 = 0.25 = 25% = 1/4 = "1 chance in 4" = "odds of 3 to 1 against."
How do you find the range of standard deviation?
Standard deviation is not a range. It is a single number that represents how much the data is a set of observations varies about the mean. Mathematically it is the square root of the sum of the squares of the differences between the samples and the mean divided by N, or divided by N-1. The decision of N or N-1 depends on whether or not the mean was also calculated with the calculation of the standard deviation. If it was the same calculation, use N-1, it the mean was known beforehand, use N.
For clarification of parenthesis, and use of N or N-1, see the Related Link below.
What is a region in an atom where there is a high probability of finding electrons?
The electron cloud. The atomic radius roughly describes the distance from the nucleus to the electron cloud.
What is the difference between Sampling error vs sampling bias?
Sampling error leads to random error. Sampling bias leads to systematic error.
How do you calculate mean median and standard deviation?
The mean is the sum of each sample divided by the number of samples.
The median is the middle sample in a ranked list of samples, or the mean of the middle two samples if the number of samples is even.
The standard deviation is the square root of the sum of the squares of the difference between the mean and each of the samples, such sum then divided by either N or by N-1, before the square root is taken. N is used for population standard deviation, where the mean is known independently of the calculation of the standard deviation. N-1 is used for sample standard deviation, where the mean is calculated along with the standard deviation, and the "-1" compensates for the loss of a "degree of freedom" that such a procedure entails.
Not asked, but answered for completeness sake, the mode is the most probable value, and does not necessarily represent the mean such as in an asymmetrically skewed distribution, such as a Poisson distribution.
What does the mean absolute deviation tell you about how spread out the data are?
i dont know...... it means
The probability of flipping a coin three times and getting two heads is?
There are 8 permutations of flipping a coin 3 times, or of flipping 3 coins one time. They are, with the permutations of two heads bolded...
TTT
TTH
THT
THH
HTT
HTH
HHT
HHH
... thus, the probability of flipping a coin 3 times and getting 2 heads is 3 in 8, or 0.375.
What does a negative deviation mean?
A negative deviation means that the observation is smaller than whatever it is that the deviation is being measured from.
How many different 4 letter combinations can you make with 6 different letters?
6P4 = 6!/(6-4)! = 6 * 5 * 4 * 3 = 360 four letter permutations from 6 different letters.
6C4 = 6!/[4!∙(6-4)!] = 15 four letter combinationsfrom 6 different letters.
How many arrangements can be made with the letters sociological?
There are 12 factorial or 479,001,600 permutations of the letters in the word SOCIOLOGICAL. However, since the letter O occurs three times, the letter I occurs twice, the letter L occurs twice, and the letter C occurs twice, you have to divide that by 8 (O), 2 (I), 2 (L), and 2 (C) giving you 7,484,400 distinctpermutations.
