Question

3. (10 points) The data below are called ttable.csv on Bb. Read the data into R as a data frame "tmat" with names as shown. This data shows critical points for the Student t-distribution for degrees of freedom (by rows) 2, 3....10. Print the data frame to the screen as below. Then construct a graph as similar to the one shown below as you can Provide me the commands you used to construct your graph, and the graph itself. Hint: under help (points), look for the option type. Also, see help (legend) t01 >tmat dft10 tos 2 1.885618 2.919986 6.964558 3 1.637745 2.353380 4.540703 4 1.533206 2.131847 3.746954 5 1.475884 2.015048 3.364930 6 1.439756 1.943180 3.142668 7 1.414924 1.894579 2.997952 8 1.396815 1.859548 2.896459 9 1.383029 1.833113 2.821438 10 1.372184 1.812461 2.763769 Critical Points from the Student-t Distribution upper 10% points upper 5% points upper 1% points - - - 0- - 00 --0-- O --0--0-- - - - degrees of freedom

I only need the r code. the dataset we have is a .csv file.

Answer 1

import the data from the csv file with read.csv() function

then to plot the graph you shown, type the following commands in R

plot(x-tmat Sdf .y-tmat $t01, ylim=c(1,7), type "b", lty-"dotted", main-"critical points from Students-t distribution", xlab="Degrees of freedom", ylab="") lines (tmat $df,tmat $t05, type="b", lty="dashed") lines (tmat $df,tmat $t10, type="b", lty="solid") legend("topright", legend-c("upper 10% points", "upper 5% points", "upper 1% points"), ity=c("solid", "dashed", "dotted"))

I have posted a screenshot of the code is because it is easy to understand it with colors and alignment. I ll give you code as text below.

the idea is just plot graph of one variable first. then using lines() function you can plot remaining variable in the same graph. You will get the following graph.

Critical Points from Students-t distribution 7 Upper 10% points 6 Upper 5% points Upper 1% points 5 4 3 2 S 1 Degrees of freedom

plot(x=tmat$df,y=tmat$t01,ylim=c(1,7),type="b",lty="dotted",
main="Critical Points from Students-t distribution",
xlab="Degrees of freedom",
ylab="")
lines(tmat$df,tmat$t05,type="b",lty="dashed")
lines(tmat$df,tmat$t10,type="b",lty="solid")
legend("topright",
legend=c("Upper 10% points",
"Upper 5% points",
"Upper 1% points"),
lty=c("solid","dashed","dotted"))