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.

37109 questions
1
vote
1 answer

Fit an ARIMA model with a gap in the data

May data is structered in the following way: Week Sales 10 9 8 7 6 6 8 5 5 4 4 3 5 2 7 1 6 Therefore, when I want to make a forecast for week 10, I don't have the…
Maria
  • 21
1
vote
1 answer

Critical U value for Mann Whitney U Test at 42 / 10 samples size

I already have calculated the U-Value of the Wilcoxon-Mann-Whitney-U test, and now I want to compare it against the critical value. However, all statistical tables I have found in various books or along the internet only have critical values for a…
Regenschein
  • 113
1
vote
1 answer

In statistics, what is the reason that makes the average height replace the median height mathematically?

In statistics, what is the reason that makes the average height replace the median height mathematically? When i searched Google there are only average height available but not median height.
Victor
  • 8,372
1
vote
1 answer

How are the values in the Shapiro Wilk weight table calculated?

http://www.real-statistics.com/statistics-tables/shapiro-wilk-table/ I am trying to build a function that performs a Shapiro-Wilk test on a sample population, but I cannot figure out how the a values in the Shapiro-Wilk weight table are calculated.…
myworkaccount
  • 93
1
vote
1 answer

Shapiro–Wilk test calculation in plain terms

Could someone please explain how to perform a Shapiro–Wilk test using an array of values (e.g. (1,2,3,4,5)? I've been searching on Google, but almost all of the results show how to calculate this using R or SPSS. Wikipedia's information on the topic…
myworkaccount
  • 93
1
vote
2 answers

Fitting curve to more complicated exponential

I've got a conjecture about the relationship of a dataset. My intuition says it's a decaying exponential, but I want to know which a and b in $e^{-ax^{b}}$ best fits the data. What's the best way to go about it? Most standard stat program doesn't…
Benjamin Lindqvist
  • 3,112
1
vote
1 answer

Least-Squares Estimator in a Two-Way Layout

I'm having a bit of trouble with the following problem in statistics (particularly ANOVA): Consider a two-way layout in which the effects of the factors are additive; suppose also that there are $K_{ij}$ observations $Y_{ijk}$ per cell, where…
Chase Uyeda
  • 204
  • 2
  • 8
1
vote
2 answers

Statistics - Function of a Random Variable

I'm trying to understand this problem: question http://puu.sh/5Qrh7.png The solution is: question http://puu.sh/5QrhP.png But I have no idea how he got from the end of the first line to the second... can anyone help explain it? Thanks!
Richard
  • 133
1
vote
0 answers

What sort of thesis can be proven with factor analysis?

I am learning (or atleast trying to) factor analysis and I don't really understand what theories / thesis's can be proved with it. It is supposed to show the hidden connection (latents) between different varaibles in a dataset, though what can be…
Bloodcount
  • 115
1
vote
1 answer

Expected value for Poisson distribution

A busy intersection sees two traffic accident per month on average. Suppose the number of accidents follow a Poisson distribution. Starting from January next year, which month do you expect to be the first one in which there is no accident? I…
user115863
  • 13
1
vote
2 answers

gamma to chi-squared distribution

I was checking answers for a question and the following arised: $$ P(Y>25\mid Y\sim \mathrm{GAM}(15,1)) = P(\chi ^2>3.33\mid\chi^2\sim \chi^2(2)) $$ Now i get that chi is just a special case of gamma with $\theta = 2$ and $r=v/2$ but can i just…
WiseStrawberry
  • 817
1
vote
2 answers

Report Numbers and Rounding

I have a report that I have generated on some data. The requirements of this report in particular is that the values for every row of data should be rounded to the nearest dollar. My boss is checking this report against another similar report to see…
Peter Lange
  • 113
1
vote
1 answer

Simple stats question or am I missing something?

Preparing for my stats final here... I must be missing something really simple or this question is just too easy. Here is the question: 5. An oil prospector will drill a succession of holes in a given area to find a productive well. The…
Sam Creamer
  • 331
1
vote
0 answers

correlation coefficient problem

The national farming association has data on the amount of pesticide used per acre and the percentage of fruit that has been contaminated by insects per acre, for $117$ farms. These two variables have a correlation coefficient $r=-0.8$. For a farm…
natsu
  • 354
1
vote
0 answers

How can I compare three different variable?

I have to verify the presence or the the absence of a phenomenon in 3 different cases (A,B,C) and then representing the results in a single bar graph in order to compare the the results of the three cases together. The phenomenon to detect is…
user114333
  • 11
1 2 3
…
99 100