Mathematics Stack Exchange
Mathematics Stack Exchange

Questions tagged [statistics]

Mathematical statistics is the study of statistics from a mathematical standpoint, using probability theory and other branches of mathematics such as linear algebra and analysis.

Statistics is the science of the collection, organization, and interpretation of data. It deals with many aspects of data, which includes the planning of data collection in terms of the design of surveys and experiments. (From Wikipedia)

More specifically, mathematical statistics is the study of statistics from a mathematical standpoint, using probability theory as well as other branches of mathematics such as linear algebra and mathematical analysis. (From Wikipedia)

For questions which are more generally about collecting and treating data, it is advised that you post your question on Cross Validated and DSSE.

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Uniformly Distributed Random Variables Minimum

Let A,B,C,D,E be independent random variables, each of which is uniformly distributed in the interval [0,18]. Let X=min{A,B,C,D,E}. What is the expected value of X? Enter your answer as a decimal. I know that I need to be attempting some work,but…
user130272
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Find a 99% confidence interval for the population mean for a sample of size 36 that yields a mean of 78 and a standard deviation of 6....

Find a 99% confidence interval for the population mean for a sample of size 36 that yields a mean of 78 and a standard deviation of 6. Assume sigma, the population standard deviation, is unknown. A) (74.2, 81.8) B) (76.00, 80.03) C) (75.28,…
user141507
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Average of part of poisson distribution

Is there a way to find the average of part of poisson distribution? I tried it by finding the center of gravity of that part. However I faced the integration of factorial in the denominator of the pmf of poisson distribution Thanks
Mohammed Alnahhal
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Normal Distribution - Statistics

True or false statements The central limit theorem implies that any sample of any size can be approximated using normal distribution. Let X be a normal random variable with mean 3 and variance 16. The value of k that satisfies P(4 less than or…
Scott Goddard
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proving a complete sufficent statistics

Suppose that $ X_1,\ldots,X_n$ are iid poisson($b$); $c = b^2$ and $S_n = \sum X_i$ To Show that $S_n$ is a complete sufficient statistic for $c$. I can prove using exponential family that $S_n$ is sufficient for $b$, but how may I prove it for…
Enas
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Multiple measurements per person per treatment

Suppose I wish to assess reaction time of individuals before and after treatment. Now to analyse the results I could use a paired t-test or if I had additional treatments, I could use a repeated measurements ANOVA. These approaches however assume…
Kenshin
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Choosing constant to minimize mean square error

Can you please help me show the statement below? I am not exactly sure where to start.
icobes
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Logic behind combinations with repetition?

I've read the stars and bars analogy, but it really doesn't make sense to me. The way I see things, combination with repetition of say 5 of the same color balls in 2 different boxes WITH REPETITION is the same as the combination of 7 different…
Jason
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Accuracy Rate with Timing

I have a test that my students take where I am interested in both their accuracy rate as well as the speed in which it took them to complete the test. The results look like this: Bob: 56/66 400s Jan: 60/66 320s I want to generate an accuracy rate…
Paul
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Uniform density question

If $X_1,X_2...X_n$ are i.i.d. $Uniform(0, \theta)$, $x>0$ and $x \le \theta$, and $\theta>0$, Calculate $t(\theta) = E(X)$ and find the Best Unbiased Estimator. a. Find $t(\theta) = E(X|\theta)$ and find the best unbiased estimator Attempt:…
lord12
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Types of data in statistics

In statistics one has 4 basic data types: nominal, ordinal, ratio, and interval. Nominal basically refers to categorically discrete data such as name of your school, type of car you drive or name of a book. This one is easy to remember because…
truе
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Quartiles and normal distribution

If $Q_1, Q_2, Q_3$ are the quartiles of a set of data and $$Q_3 - Q_2 = Q_2 - Q_1$$does that indicate a normal distribution?
Mathperson
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Why is the statement false: If a test is rejected at significance level α, the probability that the null hypothesis is true equals α?

Since the answer is false, so it just means the probability that null hypothesis is false equals α. But α is defined as the probability that null hypothesis is rejected when it is actually correct. I don't see any connections between these two…
Catiger3331
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A Flat Tire Excuse

I have this multi-part question on an assignment that I don't understand. Hopefully someone can help. There's a story that 4 students missed their final and asked their professor for a make-up exam claiming a flat tire as their excuse. The professor…
Courtney
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Mean or median when data interpretation

When doing results treatment, sometimes the mean values agree more or less with the median, but sometimes not. Thus using one or other value may change the final results. Then, is there any criteria that could be followed to know when it is better…
Katz
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