percentage

  1. A

    Statistical test for comparing percentage not mean

    Hi, I am wondering what test should I use to compare two percentage value from two different observations. Let's say I have a damage of crop 15% versus 2% in control, is there a ways to statistically test the significance between the two values? Not sure if this make sense statistically...
  2. S

    Using percentage for 2-way Anova

    Do I have to label my data as percentage in SPSS? I ran a two-way anova, and the p-value was 0.00 but when I did a bar graph, the difference was not significant at all.
  3. C

    Compare Percentages

    I have some survey data and know the number and percentage of "yes" responses. How do I determine if any of the percentage yes regional responses are statistically different from the national yes response percentage. Thank you in anticipation.
  4. W

    Standard Error associated to a variable percentage

    Context: I am a programmer, not a statistician, and I have only some vague ideas of statistical concepts. Also, my english is far from perfect, be patient please. My client needs an estimate of the percentage of taxes he is going to pay, based on what happened in the recent past. He needs...
  5. B

    WTI price vs. Drilling Cost Index

    Hi Folks, I have 2 datasets, each recorded on a monthly basis. The first dataset is the average monthly oil price. The second is a price index for drilling cost. I was to calculate what % change in drilling cost to expect with a 1% change in oil price. The data set spans 8 years and you see a...
  6. T

    Random Odds and Percentage Question

    Hi Everyone, I have a random question related to odds and percentage that I can't figure out. Does this statement in terms of the percentage difference sound true? "The odds for students in group A to graduate are 5.03 (11,734 group A students graduate and 2330 do not) and the odds for...
  7. S

    [R] Prevalence by site. Stuck after fisher.test and pairwise.t.test

    Hi, I run into a problem I can't solve and I got stuck doing the pairwise.t.test. I'll try to give you as many details I could so maybe you can help me out. Thanks in advance. I'm studying the prevalence of one parasite on a host from different localities. I do it by assigning presence...
  8. T

    Senslope as a percentage

    Hi, I found a way to express the nonparametric senslope (which is a median slope joining all pairs of observations) by dividing the senslope by the same data mean value. I have done this for all observations (For example: number of injuries observed per quarter over 6 years). My question...
  9. R

    Percentage Prevalence comparison (non-independent groups)

    Hi all! I have a dataset which I think could potentially be very exciting but I am struggling to find how to analyse it! We have gathered lots of information on the percentage if individuals who exhibit different forms of the same class of behaviour (categorical data- present/absent). All...
  10. J

    Pre/Post Comparison of Percentages, Two Populations

    I would like assistance in selecting tests for two scenarios. I am simplifying a bit here, but basically I want to do a comparison of the percentage of patients who come in for a second appointment, comparing 2011 against 2012. 1) In the "Ideal" case, the two populations are separate. What...
  11. C

    Analysis of Multiple Sites (vegetation) with multiple categories/ranks - HELP!

    I need some advice (and note, I am NOT a stats pro, excel yes, but have only used SPSS and R once) Short story is, I have done a vegetation survey on a gecko tree shelter sites. There are 20 shelter tree sites in each grid. Each shelter tree is I.D. as A(transect line) 0(distance x15m). So A0...
  12. S

    Please help!!

    Hello , I started a Statistics class a few weeks ago and i'm still pretty lost. Could someone explain to me how I should resolve this following problem ? Please. On the math SAT taken in 1994, the average score for men was 500 and the average score for women was 460. The histograms for...
  13. N

    t-test on percentage

    Hi all, Pretty simple question: I have two mean performance scores in percent, one is 70% +/- 3(SEM) and one is 95% +/- 1. Someone said I shouldn't do a t-test to compare these since data can't be normally distributed. Is that true? How would I compare these means then? thanks!
  14. Z

    How to generate a table with weighted values and percentages of the variables used?

    Hi all, I've been looking all over the web for a solution to this but to avail! So, I'm turning to this forum for a solution, if it exists! I want to generate a cross tabulation (between 2 variables) in Stata and have the resulting table to show both the weighted values and the percentages...
  15. J

    Percentage of data points in distribution

    Hello, I have a sample of data for which I have figured out that the population mean for the height of US 12-year-old children is μ = 150 cm with σ = 6 cm. The heights are normally distributed. I now need to figure out the percentage of children have heights between 141 and 159 cm. Any help is...
  16. F

    HELP regression with percentage and current $

    Hi i am trying to construct a regression with inflation as my dependent variable and gdp and income as my independent, but i am not sure if it can be done as inflation is a percentage where as income and gdp are in terms of current $. does that factor make a difference in my ols...
  17. S

    STATA HELP - How can I tell if the percentages are different statistically?

    Hi, I am trying to compare the percentage of students in reading, math and science (by school, and by subject). My table looks like this. reading math science School A 20% 20.6% 19.4% School B 28.9% 28.3% 25% School C 25% 7.7% 44% School D 15.2%...
  18. J

    Standard deviation as a percentage

    Hi i'm new here and have a really quick question, How do you interpret a standard deviation given as a percentage (in this case 20%)? I need to use the variance in further calculations (working out type i and ii errors), the data is normally distributed, and the sample size is 30, i have...
  19. S

    Comparing percentages

    I am doing a study, and have gathered the following data: A patient population was divided into 3 categories: Young patients (n=19) / Middle aged patients (n=66) / Old patients (n =20) Based on a questionairre, we have categorized each patient into 2 categories: "Yes family history of...
  20. J

    Recurring Event, Probability of Totals

    Hi. I'm actually not working on homework, but trying to make odds tables for a card game called Summoner Wars to practice/learn math for fun. It's a typical dice battle game, where various characters roll varying amounts of dice to attack. For each die, if they role a 3, 4, 5, or 6, it...