I need help on 4b please :( 4.) ‘Warpbreaks’ is a built-in dataset in R. Load it using the function data(warpbreaks). It consists of the number of warp breaks per loom, where a loom corresponds to a fixed length of yarn. It has three variables namely, breaks, wool, and tension.
a.) Write a code (Hint: a logical expression) that extracts the observations with wool type A and tension level M. Assign it to the object AM.warpbreaks *(This is done)* b.) For the ‘AM.warpbreaks’ dataset, compute for the mean and the standard deviation of the breaks variable for those observations with breaks value not exceeding 30. data(warpbreaks) warpbreaks <- data.frame(warpbreaks) AM.warpbreaks <- subset(warpbreaks, wool=="A" & tension=="M") *> mean(AM.warpbreaks<=30) >sd(AM.warpbreaks<=30)* This is what I understood this problem and typed the code as in the last two lines. However, I wasn't able to run the last two lines while the first 3 lines ran successfully. Can anybody tell me what is the error here? Thanks! :) -- View this message in context: http://r.789695.n4.nabble.com/how-to-find-the-mean-and-sd-tp4712141.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
