Please use RStudio answer these questiones and give the R command, please load d
ID: 3142552 • Letter: P
Question
Please use RStudio answer these questiones and give the R command, please load data use data:
Problem 1. (10 points)
Define two variables, fake.mean <- 10 and fake.var <- 8. Write an expression for aa using these placeholder values. Does it equal what you expected given the solutions above? Once it does, write another such expression for ss and confirm.
Solution
Type your answer here
Problem 2. (10 points)
Calculate the mean, standard deviation, and variance of the heart weights using R’s existing functions for these tasks. Plug the mean and variance of the cats’ hearts into your formulas from the previous question and get estimates of aa and ss. What are they? Do not report them to more significant digits than is reasonable.
Solution
Type your answer here
Problem 3. (10 points)
Write a function, cat.stats(), which takes as input a vector of numbers and returns the mean and variances of these cat hearts. (You can use the existing mean and variance functions within this function.) Confirm that you are returning the values from above.
Solution
Explanation / Answer
Problem 1
aa <- 10* (fake.mean) + 5*(fake.var) : 140
ss <- 10* (fake.mean) - 5*(fake.var) : 60
Problem 2
mean_hwt <- mean(cats$Hwt) : Answer is 10.63056
variance_hwt <- var(cats$Hwt) : Answer is 5.927451
stand_dev_hwt <- sd(cats$Hwt) : Answer is 2.434636
aa <- 10* (mean_hwt) + 5*(variance_hwt) : Answer is 135.9428
ss <- 10* (mean_hwt) - 5*(variance_hwt) : Answer is 76.6683
Problem 3
cat.stats <- function(a)
{
mean <- mean(a);
variance <- var(a);
return(c(mean,variance))
}
temp <- cat.stats(cats$Hwt)
> temp
[1] 10.630556 5.927451
Which is the right answer. Please also find below complete code.
library(MASS)
data(cats)
fake.mean <- 10
fake.var <- 8
#Problem 1
aa <- 10* (fake.mean) + 5*(fake.var)
ss <- 10* (fake.mean) + 5*(fake.var)
#Problem 2
mean_hwt <- mean(cats$Hwt)
variance_hwt <- var(cats$Hwt)
stand_dev_hwt <- sd(cats$Hwt)
aa <- 10* (mean_hwt) + 5*(variance_hwt)
ss <- 10* (mean_hwt) - 5*(variance_hwt)
#Problem 3
cat.stats <- function(a)
{
mean <- mean(a);
variance <- var(a);
return(c(mean,variance))
}
temp <- cat.stats(cats$Hwt)