‘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`

.

b.) For the `AM.warpbreaks`

data set, compute for the mean and the standard deviation of the breaks variable for those observations with `breaks`

value not exceeding 30.

My code for 4a) (However, it didn't work. Can somebody help me how to solve this problem?)

`warpbreak <- data(warpbreaks("breaks", "wool", "tension")) AM.warpbreaks <- c('','type A','level M') `

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#### Best Answer

Here you go:

`data(warpbreaks) warpbreaks <- data.frame(warpbreaks) AM.warpbreaks <- subset(warpbreaks, wool=="A" & tension=="M") `

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