# homework help

1. ### Having a girl the same as AT LEAST one girl? CONFUSION!!

It’s a combinatorics project for my beginner stats class. I’ve done the project several times and keep getting it wrong. The question reads: “ Is having a girl the same event as having AT LEAST one girl?” AND then it asks me: “Is it possible to calculate these probabilities?” This project is...
2. ### poisson distribition question

Hello everyone, I don't really understand the answer of question a. The question was: Find the probability that on any given day there will be fewer than two breakdowns on this highwayduring the morning rush hour. Additional information: on average: 3,2 breakdowns per day occur. isn't it...
3. ### 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...
4. ### Stats Homework Help

Hey Everyone! :) I am stuck on some stats homework questions! Hoping someone can help me out.. 1. A friend flips a coin 10 times and says that the probability of getting a head is 60% because he got six heads. Is the friend referring to an estimated probability or the​ probability's true​...
5. ### Little problem that I'm struggling to solve...

The proportion of smokers in a certain population is 25%. What is the probability that smokers' proportion in a sample of 40 people randomly selected from this population will be below (strictly less than) 20%. Surely you would use the binomial table N = 40 P = 0.25 X = 8 (since below 20% =...
6. ### Standard deviation comparison question

Two college roommates have each committed to donating to charity each week for the next year. The roomates' weekly incomes are independent of each other. Suppose the amount donated in a week by one roommate is approximately normal with mean $30 and standard deviation$10, and the amount donated...
7. ### hypothesis testing, stuck at finding standard deviation

here's the actual question: The calculated nitrogen content of pure benzanilide is 7.10%. Five repeat analyses of "representative" samples yielded values of 7.11%, 7.08%, 7.06%, 7.06%, and 7.04%. Using an ALPHA level of size 5%, can we conclude that the experimental mean differs...
8. ### Finding P(AnB') (Homework)

Hi there, this is my first post on this forum. I am trying to find the probability of P(BnA') the data given is: P(A) = 1/3 P(B) = 1/3 P(AnB) = 1/10 My attempt: P(A') = 1-(1/3) = 2/3 P(BnA')= P(B) * P(A') = 1/3 * 2/3 = 2/9 The reason I think what I did was wrong is because I...
9. ### Which Statistical Analysis would I use?

I am writing a fake study. In the study there are 3 groups which correspond to times. (1:00pm, 2:00pm and 3:00pm) The participants took a "cognitive enhancing drug" at these time intervals and I am trying to assess which time is the most effective. Performance measures were taken (4...
10. ### Need Help Statistics Homework

Hi, This is my test for homework on statistics i'll be very grateful if someone can help me with it
11. ### Genstat help

Genstat input - which structure should I use? Hi all, I'm doing a statistics unit as part of my uni degree and I'm having some trouble with an assignment question. We were given a set of data to analyse and I cannot work out which way to put it in genstat. All the options I've tried give the...
12. ### Mixed Poisson Distribution Help

Question: The number of accidents follows a Poisson distribution with mean 12. Each accident generates 1, 2 or 3 claimants with probabilities 1/6,1/3,1/2, respectively. Calculate the probability that there are at most 3 claimants. Attempt: E(N) = 12[\frac{1}{6}+2*\frac{1}{3}+3*\frac{1}{2}]...
13. ### 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...
14. ### Guidance with a random variable problem needed

Hello. So I have been trying to solve this problem on my statistics course and I'm having a lot of trouble: "In BME Bioinstrumentation lab, each student is given one transistor to use during one experiment. The probability a student destroys a transistor during this experiment is 0.7. Let...
15. ### Need a way to rank the products from data

Hi All. I have a set of data for different products. I want to grade the products from 1 to 4. With 4 being the best. Please tell me how to do it? For the data below: 0 means best product and 8.95 means worst product. Product A = 8.95 from Manufacture A Product A= 0 from...
16. ### How do you find equally likely possibilities?

I have attached a homework problem to this post. It asks what the probability is that all 4 watches of a selection are inaccurate when the manufacturer claims that .05% of all its watches are inaccurate after a year. This is where I get so tripped up, I know that Probability is # of...
17. ### validity of regression assumptions on residual plot

I am learning regression course.For a homework given the residual plot I have to analyze it.This is how I interpreted it.I want to know if there are any wrong interpretations. 1)Since the variability at each x is not the same,there is non constant variance. 2)The residuals are not randomly...
18. ### Fieller-Hinkley Ratio of Correlated Random Variables: Question On Applying Theory

I am a senior in college writing a thesis analyzing and critiquing government income transfer programs, such as SNAP (food stamps). Here is my issue. I am using data collected from the consumer expenditure survey, which will typically provide means, sample sizes, and standard errors. I am...
19. ### Help regarding z-scores and probabilities?

Can you help me understand how to do these 3 problems? Be specific, please. Here is my homework, word for word: Here we are given the probability, say .9 and we find the values of the random variable (-a and a) that determine a probability of .9 on a standard normal distribution...
20. ### plot histogram in r

I have the following data set: \begin{tabular}{|l c r|} \hline X & Y & Type \\ \hline 32 & 48.5 & A \\ 36.3 & 42.9 & A \\ 45.8 & 75.8 & A \\ 60.5 & 5457.6 & B \\ 12 & 6666 & B \\ 24.2 & 48.5 & C \\ 271 & 2796.6 & C \\ \hline \end{tabular} Now I have to draw histogram of the...