1. L

    Mean and Variance of estimators

  2. B

    Probability Distribution of Cars Sold

    Hi, I'm struggling with where to go with the following problem: The probability distribution below is representative of x, the number of cars sold within a single day. x = 0, 1, 2, 3, 4 P(x) = 0.1, 0.4, 0.3, 0.2 I calculated the standard deviation and mean, which I believe 0.917 and 1.6...
  3. U

    Hypothesis testing for 2 sample proportion

    Previously, the manager measured that the machine effectiveness was at 67.3% with a sample of size of 9. The team has made some improvements by reducing the time of changeovers, major stops and speed loss. Since those improvements, the manager has measured a rate of effectiveness at 78.2% with a...
  4. J

    If mean is between two values, generate response?

    Hi, I am new to Stata and was wondering if it has a way to do something. I have tried researching a lot and can't find anything but im not sure if that's because I'm explaining it badly. I have data where people take a depression test and in the data they all have a score for this test. I want...
  5. S

    Comparing average of two results!

    So here is a question which asks me to compare the mean results. So I calculated the mean number of deaths per 100000 people i.e (2479/216,565,318)*100000 = 1.14. So what to say? The per-day deaths of 2019 were greater than that of in 2020. That's it?
  6. A

    Can I exclude outliers when calculating mean or standard deviation (small-sample)?

    Hey, I am analyzing my results for a high-school biology paper. My data set consists of 20 groups in total, each having 4 repeats, so each is a small sample. I have a few (4) outliers that have a value lower than the control group (which is practically impossible and thus certainly the effect of...
  7. S

    Finding sample mean for normal distribution

    Hello friends, I require help on the below question on normal distribution. "An e-commerce company tries to settle the customer complaints on refund within 5 days. If a refund is not processed within 5 days, then the company has to provide coupons for Rs.500 to the customer. If the company...
  8. R

    Ordinal Model: Acceptability/alternatives to using mean and weighting factors

    I've been asked to validate a model created by someone else and need some help on how the final score is calculated. Have put lots of detail; apologies for the post length. The output (dependent) variable is ordinal scale with 5 points (i.e. 1-5) representing an assessment of risk (not risky...
  9. E

    Overlapping confidence intervals and p values

    Hi, I've been given the mean and 95% confidence interval (CI) of two independent groups and asked if they were satistically significantly different or not? I know that if the CIs of the two groups don't overlap at all, then they can be considered as significantly different. However if the CI do...
  10. D

    Back-calculation (a posteriori) of the minimum sample size for a mechanical experiment

    Hello, I want to back-calculate the minimum sample size for a mechanical experiment. I have a known mean and standard deviation of a statistical population. From the statistical population I chose two samples with means and standard variances I could estimate. My question is: How can I...
  11. J

    Calculation of overall ranking from mean, SD, and Z score

    Hey everyone, I was hoping someone could help me. Im applying for a job, and am trying to work out my overall ranking in two seperate exams so that I can include this in the application. Could someone please tell me if my calculation is correct? I have attached the file with my calculation...
  12. F

    Determining significant difference in mean ratings between two products

    Hi all, I have gathered 180 respondents and asked them to rate two products (so each respondents rates both products). The only difference between the two products is that one product has an extra feature and the other does not. Now I want to know whether there are significant differences...
  13. P

    Which one to choose? Mean or Median

    I have the past two months vehicle arrival time data for a particular vehicle. To find the consistency of arrival time which one should I go for? Mean or Median? Thanks Prashanth.
  14. R

    Normal Distribution of multiple Std.Dev´s and Means

    Is there a way to calculate the Normal Distribution of a set of multiple Standard Deviations (SD) and Means (µ)? I am afraid I do no have Access to the raw data from which the SD´s and µ´s were calculated. Many thanks in advance
  15. A

    Can I compare results from 5 point likert scale to results from 4 point likert scale?

    Can I compare mean (descriptive analysis) from 5 point likert scale to a mean of 4 point likert scale? 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,
  16. H

    Statistical power of two dataset

    Hi All, I would like to inquire how to decide whether Dataset A or Dataset B would be reliable based on their coefficient of variation, number of data points and mean value. What kind of factors could be considered? I am not searching for the direct answer but rather to jump into the...
  17. A

    How can I find an interval estimate for the mean of a Weibull distribution?

    I have a sample of n = 75 taken from a Weibull distribution and have computed mle estimates for the scale a and shape b parameter. The mean of a Weibull distribution (2 parameter) is given as u = a^(-1/b)*gamma(1+ 1/b) In which case I can find an estimate for u by simply plugging in the mle...
  18. M

    Hypothetical Statistics Question Regarding Class Curve, Standard Dev, and Mean

    Theoretical question: So say there is a course where if you score two standard deviations below the mean, you will fail the course. The class average will be roughly a 75%, not sure what to set as the baseline for standard dev, and say 150 people are in the class. One person is added to the...
  19. L

    Merits and Demerits

    What is the merits and demerits of mean median and mode? I have already found a link discussing the topic I want to that is helpful or not.