Tagged Questions
-3
votes
0answers
48 views
How to calculate the equation of a curve?
How to calculate the equation of a curve ? Following are the Data for the curve.
...
-1
votes
0answers
35 views
Statistical Analysis- Pre and Post-survey Data Analysis [closed]
I am doing a research project on whether or not students are aware of the benefits of graduating from high school. I gave students a pre-survey, then gave a presentation, then gave the same students ...
-1
votes
1answer
17 views
Relationship between two variables that does not seem correlated [closed]
I want to know the relationship between age and cholesterol level in a certain population. I have gathered a 200-person sample. After visualizing the $(age, cholesterol)$ pairs as a scatter point ...
1
vote
0answers
37 views
How to understand the task about bootstrap?
I have the following task. Let $X_1,\ldots,X_n$ be a sample (i.i.d.), $T_n = \overline{X}_n^2=\left(\sum\limits_{i=1}^nX_i\right)^2,$ and $\hat\alpha_k ...
1
vote
1answer
24 views
Box Plot Log Scaled?
When making box plots to represent data, is it logical to set our axis scale to logarithmic? Or does that defeat the whole point of a box plot?
0
votes
1answer
30 views
How are user opinions compared?
Consider a situation where people are asked to rate a product on a scale of 1 to 5.
Product A has a rating of 3.95 based on 15,000 ratings. Product B has a rating of 4.2 based on 1000 ratings.
...
1
vote
1answer
71 views
Group mean vector and common group covariance matrix in discriminant analysis?
I'm looking over the answers for old statistics exams in preparation for my own exam, while reviewing a question concerning discriminant analysis I found something really odd.
I have input variables ...
1
vote
0answers
40 views
Classification: Why k-Nearest Neighbor method is more appropriate for a Mixture of Gaussians?
I'm reading a book named "The Elements of Statistical Learning" in which it states 2 scenarios when we are trying to predict the class label:
Scenario 1: The training data in each class were ...
0
votes
0answers
69 views
Problems with Percentage Change for Trending data [closed]
Firstly, I have a very minimal understanding of any high level mathematics but I'm hoping this has an fairly basic answer. I searched other questions before posting this and didn't find anything ...
1
vote
0answers
44 views
How can I create a good subset of data proportional to the full data set
I am programming a neural network and I need to use some data to train it.
I am following the steps of an experiment which tried to predict direction of stock price index movement using neural ...
1
vote
0answers
28 views
How to find BUE of N? where $X_i$ iid $ P(X_i=j)=1/N$, for $j=1, \cdots, N$
Let $X_1, \cdots, X_n$ be iid with $P(X_i=j)=1/N$, for $j=1, \cdots, N$, where $N$ is an unknown positive integer.
I would guess that the order statistics $X_{(n)}$ is the complete sufficient ...
0
votes
0answers
70 views
Test of goodness of fit - normal distribution of file sizes on HDD
I'm trying to prove, that sizes of files stored on HDD comes from normal distribution.
I already made a java code that gave me list of all files on disk with filesizes in Bytes:
...
0
votes
0answers
56 views
maximum likelihood discriminant rule
I'm trying to use maximum discriminant rule to classify objects in my database. Could, please, somebody clarify the following for me:
For example we have 3 groups and we already know what groups our ...
2
votes
1answer
116 views
Data Type Classification in Statistics
It is my understanding that in statistics one has 4 basic data types:
nominal, ordinal, ratio, and interval.
I see cases where people refer to "count data" (which is a random variable whose range is ...
0
votes
1answer
45 views
Determining Sample Size - Design Problem
I have a hypothetical problem were say I have a sample size of about 5000 people. I then will collect data on them say, how man calories of food they eat per day for a month. Now I can't obviously run ...
1
vote
1answer
74 views
0
votes
1answer
36 views
Finding outliers in a linear series
I have a series of observations made against time. Given perfect observations, the trend should be reasonably linear. As I expect there to be measurement errors, I wish to exclude them from further ...
0
votes
1answer
34 views
Determine a curve's dominant direction over time
I have a sequence of numbers in a certain order, for example
{60,61,62,1,63,,64,102,65,66,200}
If this is drawn as a graph, this will be a curve going upwards, but with some aggressive jumps upwards ...
1
vote
1answer
139 views
What is the distribution of a data set
I understand what the probability distribution is.
I also have a personal understanding/interpretation of the concept of distribution of a dataset. Whenever I see this expression I imagine a graph ...
0
votes
1answer
46 views
arctic sea ice data by year
I want to demonstrate the usefulness of regression lines to my class, and I was hoping to do so with some data about the Arctic sea ice. What I'd like is the maximal area covered by the ice per year, ...
0
votes
1answer
128 views
Given a set of data (distance vs time) obtain a closer approximate for velocity
This is actually a physics experiment. I've collected a set of data
Distance and time it takes for a cart to move down an incline plane. From here, I've calculated the average time (...
0
votes
1answer
138 views
Html Tag counting - Rate of Change formula
I've been trying to a find a statistics-esque formula for calculating the rate of change for html tags which are either added or removed from various websites.
So, for example, with the scraper I'm ...
0
votes
0answers
40 views
How to quantify the volitility of a time series data?
I am currently working on a time series data and I would like to quantify how volatile it is.
Here volatile I mean how "shaky" the series is.
If the series is smooth than it is not volatile.
I have ...
2
votes
2answers
108 views
Working out the “best” score based on quantity and ratio
I'm not an expert with mathematics so I hope I'm posting in the right place!
I've got a lot of products which can be rated good, bad and OK by a user. What I'm having trouble with is finding which is ...
0
votes
3answers
73 views
preliminary evaluation for forecasting models
Suppose I would like to use a method for data prediction, and that I have some empirical data (i.e., sequence of samples of the form [time, value]). Would it be possible to know in advance, based on ...
1
vote
2answers
126 views
Trying to find a meaningful statistical indicator to reflect user interaction with a website
A given user can interact in multiple ways with a website. Let's simplify a bit and say say a user can:
Post a message
Comment a message
"like" something on the website via Facebook
(after that we ...
