1. S

    Statistics: Sampling Distribution Problem with Dice

    Roll a dice five times. Record the results in Sample 1. Repeat the experiment for Sample 2, 3, and 4. In a live classroom setting, actual survey data is used. In this knowledge check online environment, please use the following data: Sample 1: 2,2,3,4,5 Sample 2: 4,1,5,5,6 Sample 3: 1,5,5,3,4...
  2. M

    Expectation and variance of top 10% of any normal distribution

    Short: With the standard curve (i.e. mean=0, std dev=1), does the top 10% form its own normal distribution with the expectation about 1.74 and the standard deviation about .40? Long: I wrote a little program that takes the numbers 0.005,.015,.025,...,0.995, which is 100 numbers. I take...
  3. A

    Probability based question

    Consider two independent events, A and B, where the P(A) is 0.45 and the probability that A does not occur or B occurs is 0.70. Determine the probability that event B occurs. Any help is greatly appreciated :)
  4. G

    Multivariate Probability Distribution

    Question: f(x, y) = 1, where x,y are between 0 and 1 OR = 0, elsewhere a) What is P(X - Y > 0.5)? b) What is P(XY < 0.5)? Honestly I have no idea how to go about this question. Can anybody point out how to get it started?
  5. B

    Experimental Design - Distribution Question

    Hi, I'm studying a module called Experimental Design. I don't think my question is too difficult but I can't get my head around it. Background: Clinical trial conducted on Mars comparing two treatments A and B on frostbite. Allocation is simple randomisation, Pr(allocation to A)=1/2. So I have...
  6. H

    Analysis of K-fold Cross Validation

    Hello, I'm in a machine learning class right now and having difficulty with some problems. I'm pretty much trying to figure out the correlation between model coefficient estimates over different folds during cross-validation. The assumption of the model is Y = β + e such that E(e) = 0...
  7. A

    Density curve

    =1/2xbasexheight cannot work it out??? tried so many time
  8. A

    Unusual values

    I am stuck on how I got 2? Can someone help me I remember doing it but I have totally forgotten.
  9. A

    What is the standard deviation of the measurements coverted into Celsius?

    A temperature measurment F in degrees Fahrenheit can be converted to a measurement C in degrees Celsius using the formula C=(5/9) (F-32). Suppose 10 measurments in Fahreheit have a mean of 86 degrees and a standard debiation of 3.4 degrees. What is the standard deviation of the measurements...
  10. A

    Help with post hoc test

    Hi, I'm doing a study into the factors which cause dogs to develop noise phobias. One of my factors is the breed of dog. I have seven groups of dog breeds and have a number of dogs which do and do not have noise phobia for each of these seven groups. I carried out a chi squared test (because...
  11. X

    fisher information comparison?

    The aim is to estimate the probability of success $θ ∈ (0, 1)$ of a certain event. You have two options to sample: a) $X_1, X_2, \ldots , X_n$ from $\operatorname{Bernoulli} (θ)$ distribution $f_{X_1} (x, \theta) = \theta^x(1 - \theta)^{1-x}, x = {0, 1}.;$ b) $Y_1, Y_2, \ldots , Y_n$ from a...
  12. P

    Combined likelihood and max likelihood estimator of two normal distributions

    Hi guys ive been attempting a bank of revision questions in preparation for exams and I cannot seem to work out this question. For part a am I correct in assuming you take the log likelihoods of each distribution and add them together to combine the likelihoods? For part b I cannot seem where...
  13. J


    The table shows the number of boys and the number of girls in each year group at Springfield Secondary School. There are 500 boys and 500 girls in the school. Year Group Number of boys Number of girls 7 100 100 8 150 50 9 100 100 10 50 150 11 100 100 Total 500 500 Azez took...
  14. J

    Statistics Help - Linear Models

    I am in a Linear Models course and I am having trouble with this probelm: Consider an experiment with a two way treatment structure having three rows, two columns and four observations per treatment combination in a completely randomized design. a. Specify the population marginal means (PPM)...
  15. E

    probability problem

    n balls are randomly distributed among three boxes. Find the probability of (a) exactly two empty boxes; (b) exactly one empty box (c) no empty boxes. so the answers are (a) 1/3^(n-1) (b) [(2^n)-2]/3^(n-1) (c) [3^(n-1)-2^n+1]/3^(n-1) I don't understand why the denominator is 3^(n-1) and why...
  16. D

    Reporting results p > .05 justified?

    Hi all, Recently I did a field study where I investigated recycling behaviour in the office. We did a baseline and post-intervention measurement of the respons rate (i.e. how much of the total amount of a certain type of waste ends up in the right bin?). For 2 x 2 weeks we collected and...
  17. M

    Can someone please help me interpret a cross correlation plot?

    Hi everyone, I was wondering if someone could help me by explaining in simple terms what this cross-correlation plot is showing? The two time series I am showing are: X = Changes in charcoal particles in sediment throughout time. Y = Changes in spruce pollen percentage throughout time. I am...
  18. K

    Need help reverse-engineering the logic

    Hello, Not a typical question... I have these samples of data, and I know they produce results below. I know percentages are calculated based on comparison of stimulus to marker. Marker is the base level. Stimulus is the actual experiment. However, I can't reproduce the mathematics behind it...
  19. J

    A certain experiment is to be performed until a successful result is obtained.

    Im not sure what distribution method to use here. Over all though im not sure what to do here.. A certain experiment is to be performed until a successful result is obtained. The trials are independent and the cost of performing each trial is 25,000 dollars; however, if a failure results, it...