Let X equal the forced vital capacity (the volume of air a person can expel from his or her lungs) of a male freshman. Seventeen observations of X, which have been ordered, are 3.7 3.8 4.0 4.3 4.7 4.8 4.9 5.0 5.2 5.4 5.6 5.6 5.6 5.7 6.2 6.8 7.6 (a) Find the median, the first quartile, and the third quartile. (b) Find the 35th and 65th percentiles.

#data anlysis for using weighted linear regression x=c(2,2.4,3.1,3.5,6.4,6.1,7,11.5,10.9,12.2,12.6) y=c(10.1,11.4,24.2,26.5,66.8,53.8,71.1,132.7,108,126.2,140.7) data=data.frame(x,y) m1=lm(y~x,data) plot(x,y) #from the plot, I will divide the data according to x values 2-4, 6-8, >9 group1=data[1:4,] group2=data[5:7,] group3=data[8:11,] a=c(mean(group1[,1]),var(resid(m1)[1:4]),mean(group2[,1]),var(resid(m1)[5:7]),mean(group3[,1]),var(re...