# statistic

1. ### Correlation Coefficient.

1) If the correlation coefficient between two random variables X and Y is 0.5, then the correlation coefficient between 2X-4 and 3-2Y is? a. 1 b. 0.5 c. -0.5 d. 0 1) If the correlation coefficient between two random variables X and Y is 0.3, then the correlation coefficient between (2X+3)/5...
2. ### Probability HW help

I need help with these problems. I worked them out, got answers, and checked the back of the book to see if I got them correct. A pair of six-sided balanced dice are rolled. What are the probabilities of getting the sum of the face values as follows? (a) 8 (b) 6 or 9 (c) 3, 8, or 12 (d)...
3. ### Weekly Sales - statistical analysis

I need to analyze sales on hourly level, and compare hourly sales of one day with same day in last 10 weeks. Following is the data set: -Day -Hour -Sales Trend charts are helpful in analyzing 2 to 3 days of data, more than this information don't have good presentation. Please suggest which...
4. ### Importance of vars in linear regression (R)

I have a question that is and R question and a statistical question: I am analysing sales of a retailer. These sales are related to some vars: var1, var2, var3.., varN Most of the vars are continuos. I want to analyze the relationship between sales and the vars. I have made a linear...
5. ### Survey uncertainty with a given population proportion

Hello! I have to estimate the uncertainty of the result of a survey where there sample size was defined to have an uncertainty of 2.76%, based on p a p value of 0.5. The 2.76% error is calculated assuming a 50% population proportion, which is a worst case scenario assumption: size...
6. ### Analysis of data - how to find the most relevant factors

Solved. Sorry... You can delete it.
7. ### How to calculate Huber Estimator

Hi, I would like to understand how to compute the Huber estimator. As I read, the objective function of Huber estimator is minimizing $\rho (x_i - \theta)$, where the $\rho (t) = 1/2 t^2$ when $|t| < k$ and $\rho (t) = k|t| - 1/2 k^2$ when $|t| > k$. Anyone know how to compute this...
8. ### What distribution is better in these situations?

I'm new in statistics and probability and I'm a little lost about what distribution is better in these situations: If a tumor is malignant or not --> Bernouilli Number of entries in an emergency service during a night, know that on average 20 entries are observed per night. --> Poisson Tumor...
9. ### Comparing time lag between two data sets

Hi, I am trying to compare two data sets available for x number of historical months. These are two different types of claims, i.e. first party claims and third party claims. We know that third party claims will increase if first party claims increase and vice versa, after a lag of few...
10. ### HELP - citation model in R

Hello everyone. I need help with the citation model as explained in This article "Bibliometric tools applied to analytical articles: the example of gene transfer‐related research" The model is expressed as C=KY+S C=cumulative number of citation Y=article life K=citation rate (number of...
11. ### Probability Distribution

Suppose it is known that 8% of males are colour blind. In a random sample of 500 males, what is the approximate probability that at least 10% of them are colour blind? Correct answer is 0.05. Can someone show the steps or the idea behind this question. Can someone please help me with this question.
12. ### Pillai’s Trace

Of the 4 test statistics commonly used for MANOVA why is Pillai’s Trace used most often?
13. ### What is the population parameter of interest? When the responses are normal?

The problems said: Students in Stanford are supposed to spend on average 3 hours of time per week for every credit hour they take. Last year, 263 randomly selected seniors were contacted and asked how much total time they spent on their studies over the last week and how many credit hours...
14. ### Average distance of the dart (Dartboard)

Hello I have been struggling with this questions for some time now and I have no idea how to start it. Can you guys give me some tips? "A large circular dartboard is set up with a "bullseye" at the center of the circle, which is at the coordinate (0,0). A dart is thrown at the center but lands...
15. ### plot type 'line' will be truncated to first character

For anyone that can help me this would be greatly appreciated. I have to determine the probability of a Markov chain hittng state 1 before hitting state 5, with z varying from 0 to 1 and produce a plot. The code I have so far is: trials = 1000; hitone=0; for (k in 1:20){ z= 0 + k/20 for(j in...
16. ### Choosing a representative reference value

Hello, let's see if someone can help me with this. I have a data series of a year of road traffic in a concrete point (number of vehicles/day) I want to find a stadistic, like the maximum, the mean, the mean plus the standard deviation or other that represent my data series in most of the...
17. ### Mediation analysis for two correlated mediators

Hey people, I am trying to find an appropriate mediation analysis method. I want to investigate how an INTERACTION of two variables mediates the association of two different variables. I have read about mediation analysis with one or multiple mediators, but nothing about an interaction as the...
18. ### Estimating the Average and Standard Deviation with Missing Data

I need a way to shows me how the parameters of PDF, log-normal in this case, can be estimated based on a set with missing data points at the tail end of a sample. For example, Consider we had 20 numbers with specified μ and σ, and then missed two largest number of them. How do we can estimate...
19. ### Help with statistics

Only statistics that you need to calculate for it are the means, standard deviations, and sample sizes. Here are the results: Nutrient Test statistic value P Value Calories 3.984 .000 Saturated Fat 7.613...
20. ### Help me w/ stat. project.

I'm a collage student and my final project is to research any topic, examining a single quantitative measurement and present the results. I'd like to research several aspects in regards to bulling. Such as how much has school bulling increased/decreased. If student victims of bulling graduated...