For example :

Age Range Frequency

>=15 and <=20 100

>20 and <=25 256

>25 and <=30 278

>30 and <=35...

Is this possible?]]>

But, in my opinion, two parameters are estimated: the mean is estimated by the sample mean and the variance is estimated by the sample variance (corrected). Then why shouldn't we use the t-distribution with n-2 degrees of freedom?]]>

I would appreciate your help in the following query.

I have a data set of three different groups of cancer patients and I need to show the difference in the size of the cancer in the three groups in a single graph. What type of graph would best serve this purpose?]]>

I do not know if the post head label my problem appropriately since I am quiet a beginner in this field but here it is:

My analysis is about the determinants that influence someone's chances to live in a low income area (

I have a categorical variable indicating the race of each borrower. After creating dummies with the reference category white and having included the 10 other...

Logit regression with categorical variables over represented in the sample]]>

First of all i compared the proportion of agreement(yes-yes, no-no) of them. The results was:

A-B= 78%

A-C=59%

B-C is out of my objective.

So I run a Pearson Correlation test, and the results was:

A-B=0,17 (p-value = 0,03)

A-C=0,11 (p-value=0,15)

Which test should I do to verify the correlation between these variables? Chi-square test?]]>

I want to compare the data for different emotions to see whether any two emotions have bodily sensations which occur in the...

Chi Squared test?]]>

I surveyed two groups of 50 people:

50 x people aged 40 and over

50 x people aged under 40

My hypothesis is that there is a significant difference between the opinions of people aged 40 and over and that of people aged under 40 as to whether they would consider allowing a robot perform a filling on their...

Help with choosing a method]]>

I am interested in comparing the frequency of each of these four behaviors among the high condition group to the...

Is it appropriate to use Mann-Whitney U test for each of four outcomes when outcomes are mutually exclusive?]]>

I find the mean hexadecimal color of the white paint by measuring several independent samples of Eggshell white (n=20 different paint cans) and I do the same for the Midnight black paint...

Sample size when adding two means]]>

I am prediction one-day-ahead solar energy output using 30 days historical data. The data sets are hourly, so the prediction is done hourly from sunrise to sunset.

I have doe the prediction using sliding window technique, When I am predicting 01/06, I am using 30 days historical data (from 02/05 – 31/05 ) for the training dataset that will be used to build the model, the training dataset include weather variables (global horizontal irradiance, direct normal irradiance, temperature and...

Solar energy prediction]]>

2. Assume that we drew a random sample of 300 women who had recently graduated from USC. All of these women worked full time in 2018. They earned an average salary of $42,167 (s.d. = $26,413). Based on data from the US Census Bureau, we know that the national average salary for women is $40,675.

a. USC is looking to make the case that women who have graduated from the university make significantly more than the national...

T Test word problem! HELP]]>

Came accross this website whilst trying to get somw help with a project Im doing.

Many thanks for any help.

Rob]]>

The equation is one year ahead stock returns as a function of a few...

Endogeneity and R-squared]]>

Im currently working in a research on higher education in the United States. I have searched for a database with the average tuition cost per institution (higher education) hopefully for the 1980 - 2015 period, but I have found nothing, so if anyone could point me in the right direction it would be much appreciated.

Thanks and have a beatiful day.]]>

male

1/2

neg

neg

neg

1/8

female

neg

1/4

1/16

1/2

1/4

For the descriptive part, if I got it right, I calculate the prevalence and use only the positive ones to calculate the mean. So, it would be in the male group the prevalence is 40% and mean titer X and in the female the prevalence is 80% and mean titer Y. The mean is or the...

Can you include negative results when doing statistics of antibody titers?]]>

I want to model smoking (0-1) with some socioeconomic characteristics (edu, age, cohort, sex, etc.). I have 4 waves of a survey, some respondents are present in all waves, while other started in waves 2, 3, etc. The duration between waves is also not always the same (i.g. 2 years between 1-2, 4 years between 2-3, 1 year between 3-4).

I'm not use to longitudinal analysis, so I wonder what kind of model I should use. I was first thinking to survival model (Cox), but I'm not sure, since...

What model for a discrete value with repeated observations]]>

Probability]]>

The image is from my lecturer]]>

I'm new to statistics and looking for some guidance on choosing my variables for a repeated measures ANOVA.

My data set consists of 4 dependent variables:

1. Gait speed

2. Balance test

3. Leg strength

4. fatigue rating

I'm trying to determine the difference between each of these measures when performed at different times per day:

1. Morning

2. Evening

My thought is that the Indep variable is the time of day and when running in SPSS I would enter morning and evening as the...

Repeated measures ANOVA]]>

I'm new to statistics and looking for some guidance on choosing my variables for a repeated measures ANOVA.

My data set consists of 4 dependent variables:

1. Gait speed

2. Balance test

3. Leg strength

4. fatigue rating

I'm trying to determine the difference between each of these measures when performed at different times per day:

1. Morning

2. Evening

My thought is that the Indep variable is the time of day and when running in SPSS I would enter morning and evening as the...

Repeated Measures ANOVA Inquiry]]>

1) Obtain the point predictions of

2) Obtain the predictions of

3) How are the parameters of this model estimated? Explain

How is it calculated / developed?

Photo please. Please]]>

I have a difficulty to determine the correct answer to an important question, because I heard two contrasting opinions on this.

Is it allowed to include a continuous factor (

My original intention was to determine whether age had a significant impact on my dependent variable...

Help needed - including a continuous factor in an ANOVA vs. Covariate analysis]]>

Does Physics use statistics and probability as heavily as Medicine does? My guess is No.

In Medicine, we're limited in that we can't experiment in most situations and therefore end up with conclusions drawn from analysing outcome measures that may have more predictor variables that we can conceive, yet we can only work with what we know, until we know more. We use large p-values of 5 percent. And...

How much of Science is based on Statistics]]>

Variable as confounding if it influences other factors in opposite directions?]]>

Results from 5 point likert scale: M: 3.34 (SD: .80) Results from 4 point likert scale: M: 2.18 (SD .44)

I want to compare these results, is that possible?

Thanks in advance,]]>

Suppose John chose a bag and then picked 1 coin from within, the coin was a gold coin, what's the probability

that he picked bag A ?

The answer is 0.5833 using Bayes' Theorem.

what's the probability that he picked bag A ?

Does anyone know how to calculate this?]]>

In the first test, a beetle is on his own in an arena and I measured the % of time he spends in each of THREE types of habitat (open, bush and underground). I repeat this experiment with several beetles.

In the second test, beetles are placed together with a beetle of a competing species in the arena and they are again observed for their % time in each habitat.

I want to test if the amount of...

Which stats test should I use?]]>

I am working on developing on a standardised score from a number of scores.

The values will be ranging from large to small of each score and I am trying to develop a way of proportionally measuring different data sets. I have something at the moment which is:

(x1/largest x in dataset1) x100

(y1/largest y in dataset1) x100

(z1/largest z in dataset1) x100

[and so on.. and then I find the mean of the answers.]

I then compare the mean to the another mean but from a different data...

Standardising a score of values]]>

I'm wondering which statistics should I use. I’ve conducted an acceptability judgment task using 7 point scale for 8 different conditions. My study has a 2*2*2 factorial design with two level for each factor, this results in 8 structures mentioned below.

Factor 1: A (-,+)

Factor 2: B (-,+)

Factor 3: C (-,+)

This results in 8 conditions:

Condition 1= A (+) , B (+), C (+)

Condition 2 = A (-) , B (+), C (+)

Condition 3 = A (+) , B (-), C (+)

Condition 4= A (-) , B (-), C (+)...

which test should I use?]]>

this is actually the first time I'm working on a big dataset and I really hope someone can give me some advice on how to handle missing data. I tried to find information regarding my problem but can't find any blog with the same issue.

I'm working on a dataset including different questionnaires. Some questionnaires measure the participants level of anxiety, depression etc and some questionnaires measure the same participants perception of compassion within their organisation. The...

All items missing for various questionnaires]]>

The dependent variables (company performance indicators) will also be time-series data...

Time Series Data for Business Performance: Regression Model?]]>

1) Can I use the variance of the parameter to build confidence intervals like I would with a normal distribution, ie lower 95 CI = mean -...

Fisher Matrix and Parameter Confidence Interval]]>

Thank you]]>

I have a system comprised of three probabilistic boolean timeseries and I want to simulate how two of them would react, if a certain intervention would take place (lets say, timeseries 1 can be influenced and will definitely be "0" for the next 6 observations).

(The managerial question behind this is: Would it be good, to influence a system (comprised of the three time series) such that one of the timeseries involved can only produce zeros in the near future. "Good"...

Can I use a set of LSTMs to simulate counterfactual states?]]>

We're a small packaged healthy snack company. We sell our products in a particular chain of stores and we get weekly sales data per store per product per week. Screenshot of data is attached.

We recently did a test where we applied coupons directly on to products in three stores (think of the little sticker coupons that say save $1 and you peel it off and scan it at checkout). The point of the test was to see if those little coupons resulted in a sales lift, and if so, what is the...

Advice on Statistical Test]]>

I am doing a research and will study the how user think

about shopping online.

In my questionnaire, I have 3 questions - using Likert Scale

1 - Strongly Agree, 2 Agree, 3 Nuetral, 4 - Disagree, 5 - Strongly Disagree.

My questionnaire is as follow.

1. I find that Internet is secured for shopping

2. My general intention to shop online is high.

3. I find that shopping online is convenient.

The Hyphothesis that I want to test is

H1 - Users has confidence to...

One Sample T-Test with Likert Scale Questionnaire]]>

I am looking at pre-post survey data for a college course. The survey question are looking at students attitudes on multiple subjects, from the beginning of the course to the end of the course. I used a likert scale and course instructors were hoping that the attitudes towards the topics improved.

In the pre-test I have about 598 responses, in the post-test I have about 363 responses. Some of the students who...

Missing data for a paired t-test]]>

I am currently using ARIMA and SARIMA models to forecast a company´s sales. I get the general idea of the models, but i cannot seem to understand the exact equation stata uses to predict the model´s output.

My dataset is comprised of 120 monthly observations of sales "altom" and the command i use to model the sales is the following:

arima d.altom, noconstant ar(1) ma(1) mar(1, 12) mma(1, 12)

predict model

What i want stata to tell me is the equation it uses with the command...

SARIMA Equation]]>

Also is the principle of optimising dose and schedule similar to that of finding the maximum tolerated doses (MTD) of a dual agent as in Wages method https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3521068/pdf/nihms-399865.pdf

(is can Wages...

software for phase 1 dose and schedule optimisation]]>

My name is Raphael, I'm 22 and I'm french. I am very interested in statistics although my knowledge is quite limited. I've had classes of econometrics, but we did not cover very advanced material. I'm enjoying a lot coding on Matlab for whatever project I need to deliver in class

I'm currently working on a research project involving some rather advanced econometrics and I struggle from times to times. Anyways, I have plenty of questions going though my mind right now, so...

Hi everyone!]]>

Code:

```
proc calis nobs=932 data=Wheaton;
lineqs
Anomie67 = 1.0 * f_Alien67 + E1,
Powerless67 = 0.833 * f_Alien67 + E2,
Anomie71 = 1.0 * f_Alien71 + E3,
Powerless71 = 0.833 *...
```

I'm currently working on a research project for which I need to estimate parameters on a

To put things in context, I'll start by explaining what I understood and how I...

Is this how a structual VAR works ?]]>

I am about to use cox-regression to estimate the interaction between two binary variables: Disease (1,0) and Drug (1,0).

Disease: 1=Disease, 0=No disease

Drug: 1=Drug, 0=No drug

This make the interaction a “2x2 table” (as below). Here is the SAS code:

Code:

```
proc phreg data=Data;
class Drug(ref='0') Disease(ref='0') /param=glm;
model Duration*Event(0) = Disease Drug Disease|Drug / ties=Efron rl;
hazardratio 'T1' Disease / at...
```