Question

3. [5+5+1=11 pts]

a. Draw a frequency histogram for “Temp” variable from “airquality” data. Use breaks=seq(55,

100, 5) in your hist() function. Show frequency on top of each bar. Paste your graph below.

b. Draw a relative frequency histogram for “Temp” variable from “airquality” data using the

same ‘breaks’ parameter. Add a density curve to it. Paste your graph below.

c. What kind of distribution does the data exhibit? Right skewed? Left skewed? Symmetric?

Answer 1

Solution-A:

use hist function in R ,with breaks inside hist set breaks=seq(55, 100, 5),Give title for histogram in main inside quotes.

Give the labels for x axis with xlab and set color of your choice with col

Rcode:

hist_temp <- hist(airquality$Temp,breaks=seq(55, 100, 5),main="Histogram for temperature ",
xlab="Temp",col="green",
border="orange")
text(hist_temp$mids,hist_temp$counts,labels=hist_temp$counts, adj=c(0.005, -0.005))

Output:

Solution-b:

Rcode:

hist(airquality$Temp,breaks=seq(55, 100, 5),prob=T,main="Density curve Temperature",col="green",
border="orange", xlab="Temp")
lines(density(airquality$Temp,na.rm=T),col="blue",lwd=4)

c. What kind of distribution does the data exhibit? Right skewed? Left skewed? Symmetric?

From histogram and density we could see that sample follow normal distribution

shape is symmetric