Question

how would i know which test i could use. is there a fabke perhaos where i could see which tests i could choose? Anova, t-Test, Regression, Correlation, U-Test,etc....

Mandaue Test Your Skills Biometry Researchers collected data on the diameter at breast height (dbh) and flower production for male and female trees. These data are available in D2L for download. Please use that and do not try to type all of this in. # your turn maledbh <- c(171,187.274,285,182,133,133,267,216,185,183,264,83,242,235,242,267,190,284,228) maleflowers < c(110,133,624,637,225,47,36,524,272,133,133,442,3,333,488,536,512,173,561,312) femaledbh < c(174,212,227,86,161,225,154,71,166,145,207,157,87,193,300,316,217,189,84,135,122,280,295,139,1 65,81,68,314,77,282) femaleflowers <- d2345 12,1 107,8333,512,164,1,198,22558,164,5,4 19,1482,1138,561,282,11,14870, ii 07,94 1,89,18 1,8,1,1091,3,1398) Use your knowledge of statistics and your experience with R to answer the following questions. Save and print out your R output so that we can discuss it in class. Research Question 1: The researchers want to know whether male and female trees differ in their dbh What is their independent variable? sex of tree bresst hetyldt mann-uwintrey -Test What is their dependent variable? What is the appropriate statistical test? Perform the appropriate statistical test in R. What does R report as the test statistic, the df, and P What is the statistical interpretation? What is the biological interpretation with statistical information? There whs no d n, 30, 2-30, U. 37, P045)

Answer 1

In research question 2 the dependent variable is fl0wer production. The normal population assumption is not confirmed to apply two sample t test. Hence for the first two research question U test (parametric test) is the appropriate one.

In research question 1 the pvalue >0.05 so at 5% significance level the null hypothesis cannot be rejected

Again in research question 2 the p value >0.05 so the same conclusion follows for 5% alpha ie Flower production will not differ for males and females

For research question 3 and 4 you can use correlation test

Research question 3&4)Independent variable in question 3 and 4 is the dbh of male trees and female trees respectively and dependent variable in question 3 and 4 is the flower production of male trees and female trees respectively.

Correlation test tests whether the correlation coefficient is 0 ; Null hypothesis $H_o:\rho=0$ vs $H_1:\rho\ne0$. If the test is statistically significant ie the pvalue <0.05. then based on the sign of sample correlation coefficient (r) we decide the direction of the relationship. If r is positive then we conclude that flower production increases with the increase in breast height for males.

When variables with the same characteristics are compared eg the breast height for two groups we use t test or u test . t test when assumptions for the t test are met. otherwise we go for u test

When variables with different characteristics are compared ie breast height and flower production a correlation test can be performed. If prediction is made we conduct a regression test.

There is no scope for anova in this question

Answer for the 5th question in the summary (last page) If there exist a significant relationship between dbh and flower production for males and females then we can perform a multiple regression and try to estimate the flower production by keeping gender and dbh as independent variables.