Exercise 11. Plotting the errors

Make a qq-plot of the errors you generated previously to see if they follow a normal distribution.

This exercise is part of the course

HarvardX Data Science Module 4 - Inference and Modeling

Exercise instructions

Run the supplied code
Use the qqnorm function to produce a qq-plot of the errors.
Use the qqline function to plot a line showing a normal distribution.

Hands-on interactive exercise

Have a go at this exercise by completing this sample code.

# Define `p` as the proportion of Democrats in the population being polled
p <- 0.45

# Define `N` as the number of people polled
N <- 100

# The variable `B` specifies the number of times we want the sample to be replicated
B <- 10000

# Use the `set.seed` function to make sure your answer matches the expected result after random sampling
set.seed(1)

# Generate `errors` by subtracting the estimate from the actual proportion of Democratic voters
errors <- replicate(B, p - take_sample(p, N))

# Generate a qq-plot of `errors` with a qq-line showing a normal distribution

Edit and Run Code