Mathematics Stack Exchange
Mathematics Stack Exchange

Questions tagged [descriptive-statistics]

The area of statistics that provides descriptions of data, may it be samples or the population. This includes graphical representations and numerical indicators. No information is inferred from samples about the population, as in inferential statistics.

Descriptive statistics is the process of using and analyzing statistics that quantitatively describe or summarize features of a collection of information.

Descriptive statistics is distinguished from in that descriptive statistics aims to summarize sampled data rather than use the data to learn about the population that the sample of data represents. Hence, descriptive statistics, unlike inferential statistics, is not developed on the basis of probability theory.

Measures used to describe a data set include—

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How can the median number of sexual partners be 6.1 and 3.6?

http://www.cdc.gov/nchs/nsfg/key_statistics/n.htm Median number of female sexual partners in lifetime, for men 25-44 years of age, 2006-2008: 6.1 Wouldn't it only be able to be x.5 or x.0?
user248640
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Moving Window Computation of Skewness and Kurtosis

I would like to be able to calculate Skewness and Kurtosis from a sliding window dataset in a computationally efficient manner. The dataset shall be a specified quantity with new elements replacing old (eg. FIFO queue). The answer for a similar…
MArkus
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Intuitive explanation of the formula for mode (grouped data).

The formula for finding the mode in grouped data is given by: $$ mode = l + \frac {f_1 - f_0}{2 f_1 - f_0 - f_2} X h $$ where, l = the lower limit of the modal class, $ f_1 $ = the frequency of the modal class, $ f_0 $ = the frequency of the class…
WorldGov
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A formula for getting the median of values?

I have say, i occurrences of the value x, j occurrences of the value y, k occurrences of the value z, (and so forth). I'm looking for a way to calculate the median of these occurrences in Excel without having to list out every single occurrence…
Dave
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Descriptive statistics question

Question from a homework assignment I'm working on. There are 40 students in a class. 27 are having trouble in Math, 15 are having trouble in English. 2 are having trouble in both subjects. Are the two students that are having trouble in both…
Craig Efrein
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Is there a general definition of mean value that would include arithmetic, geometric and harmonic means as special cases?

It may not be necessary to have a general definition, but it does not seem as if it should be difficult to come up with one. One requirement might be that the mean of a set of numbers must always be greater than or equal to the smallest number and…
user1153980
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Change in mean, median, variance and mode of a modified sample

Consider a set of N observations consisting of $k$ distinct values, each of frequency $f_{1}, f_{2},...,f_{k}$. The above $k$ observations once each is added to get a modified sample of $N+k$ observations with frequency$f_{i}+1$. Then what would be…
Harry
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Why The Population Mean = Sampling Distribution Mean

I'm currently learning about basic statistics and the sampling distribution. You'll have to forgive my misuse of terms as I'm still learning. My question is about how is the average of a population the same as the average of the sampling…
Nick
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Finding a threshold between two accumulations

My question: I have a list of numbers. This numbers are part of two accumulations, for each accumulation there is some unknown number of values around a specific average I don't know. How can I find a threshold between those two accumulations, so I…
fecavy
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Applications of Arithmetic mean, Harmonic mean and Geometric mean

In case where one deals with tabulated frequency distributions, which type of data is more suited to arithmetic mean, geometric mean and harmonic mean? I know how to calculate these means. However, I am confused which type of data requires…
user357434
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Figuring percentage when mean and standard deviation are given

Consider the mean combined SAT score for high school seniors is 1500, and the standard deviation is 250. Calculate the percentage of students who scored at the following levels: Below 1000. Above 1750.
Farrah Dutton
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Can I use several medians, IQRs, and N for each, to calculate the median and IQR for the composite group?

I have measurements of a group divided into subsets, with a median, interquartile range (IQR), and total N for each subset. I would like to calculate the median and IQR for the total group using this information. Is that possible? Thanks!
micturalgia
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Is there a preferred statistical way to measure diversity? If not, how to go about inventing one?

I don't know much about statistics, besides a couple of humorous chestnuts, so please bear with me. Let's say I run a corporate tax law firm in Georgia with two other white guys. We have a hundred plus associates, of which four are black, four are…
Robert Soupe
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Calculating the median when the sample size is even

In statistics the median is a point that divides an ordered data into two equal parts. By definition if $n$ is odd the median is $\frac{n}{2}{th}$ data point that is simply the middle point of the ordered data set. When $n$ is even the median is…
Asad Ali
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quantile rank formula

I am teaching a basic statistics course for psychology students. The lecturer provided a formula for the rank of a quantile rank = alpha n + 1/2, alpha being the proportion which corresponds to the quantile and $n$ the number of observations The…
blahblahblah
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