Question

This is 3 short questions that needs to be answered in R programming:

You are given a data set titled data.txt and the following code:

data <- read.table("data.txt", header = TRUE)

The dataset looks like this:

id Sex Genotype Activity 1 male ff 2 male ff 3 male fs 4 female ff 5 male fs 6 female ff 7 female ss 1.884 2.283 2.396 2.838 2.956 4.216 3.620

Question:

1. Create a table containing the sample size for each combination of sex and genotype (code in R).

2. Calculate the mean and standard deviation for each combination of sex and genotype (code in R).

3. Create side by side boxplots of MPI activity for the three types of **Genotype** (code in R)

Answer 1

Suppose your dataset is 'df'

# then for for accesing the sex and genotype use

names(df) <- c("Genotype", "Sex")

# Mean is -:

mean( df [ ["Genotype", "Sex"] ] )

# Standard deviation  is -:

sd( df [ ["Genotype", "Sex"] ] )