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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
Why can't probability be negative?
Because probability is a measure of how likely it is that some event will occur. If there is no chance at all that the even will occur than the probability is 0. If it will occur with 100% certainty, then it is 1 or 100%
A negative number would have no meaning in terms of how likely an even is to occur?
3/5=g/30
You roll a standard number cube and get a multiple of 4?
You got a one or a four. One is the zeroeth multiple of 4. Four is the first multiple of four. Any other result, such as 8, and you are not rolling a standard die.
2/9
The difference between an empirical distribution and a theoretical distribution?
Empirical Distribution: based on measurements that are actually taken on a variable.
Theoretical Distribution: not constructed on measurements but rather by making assumptions and representing these assumptions mathematically.
What is The difference between an empirical distribution and a theoretical distribution?
empirical distribution is based on your observation of out comes, it is based on real data. on the other hand theoretical is base on your theory regarding the distribution and the parameters, (i.e. normal/exponential...., u=5 vs u .5....and so on)
What is the difference between convenience judgment and random sampling?
Non-probability or Judgement Samples has to do with a basic researcher assumptions about the nature of the population, the researcher assumes that any sample would be representative to the population,the results of this type of samples can not be generalized to the population(cause it may not be representative as the research assumed) and the results may be biased.
Probability or Random samples is a sample that to be drawn from the population such that each element in the population has a chance to be in the selected sample the results of the random samples can be used in Statistical inference purposes
How can you prove the combination formula?
GENERIC:
- Let C(n,r) be the number of ways to generate unordered combinations
- The number of ordered combinations (i.e. r-permutations) is P(n,r)
- The number of ways to order a single one of those r-permutations P(r,r)
- The total number of unordered combinations is the total number of ordered combinations (i.e. r-permutations) divided by the number of ways to order each combination
- Thus, C(n,r) = P(n,r)/P(r,r) = [n!/(n-r)!]/r!/(r-r)!] = n!/r!(n(n-r)!
SPECIFIC:
- Let C(52,5) be the number of ways to generate unordered poker hands
- The number of ordered poker hands is P(52,5) = 311,875,200
- The number of ways to order a single poker hand is P(5,5) = 5! = 120
- The total number of unordered poker hands is the total number of ordered hands divided by the number of ways to order each hand
- Thus, C(52,5) = P(52,5)/P(5,5)
3/6 or 1/2 or 50%
What is the theoretical probability of rolling a number greater than a 1 on a fair number cube?
5/6 0.833333333 ect. 83%
What is standard normal variate?
It's the same as a z-Transformation.
for all xi: (xi-mean(x)) / std(x)
If there is zero deviation all the observations are 50.
Probability zero. If both dice have the same number, then the result will be even. If both dies are odd (as in the case of 5) then the sum is even. If both dies are even, the sum is also even. The only way to get an odd sum is to have one die have an odd number and the other die have an even number. That will happen 50% of the time.
The probability of both dice showing 5 is 1/36. But the two events will never happen at the same time.
3/5
What effect does sample size have on the estimate of the mean?
the larger you r sample size the better your estimate. imagine take the height of person to estimate the average high of an adult male. would one person's height be a good estimate, or would taking the average height of 100, or 5000 adult males will produce a better estimate?
Theoretical probability of rolling a factor of 10 on a number cube?
The factors of 10 are the numbers that divide 10 evenly: 1, 2, 5 and 10. To answer your question, you have to figure out what the probability of rolling one of these numbers is on a number cube.
True or false the sample mean is a point of estimate of the population mean?
Nearly true. It is a point estimate, not point ofestimate.
When do you use uniform distribution?
When, over a given range, the probability that a variable in question lies within a particulat interval is equal to the size of that interval as a proportion of the range.
In statistics which is better large sample size or small sample size?
Generally, the larger the sample the more reliable the results.
Example:
If you flipped a coin twice and got heads both times you could say the coined is biased towards heads.
However, if you repeat the experiment 100 times your results will be a lot more reliable.
What do you win if the odds are 5 to 2?
When the odds are 5 to 2, if you bet $2 on something and win then you will receive $7 The $2 you bet and the $5 you won.
There are 230300 ways.
