[R] I need help with extracting data :(

[massmatics]

So this is the question that I need help on. :(
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**.
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**. 

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')

Thanks! :)




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