Extracting vectors from data frames (dplyr)

Using the Portal data surveys table (download a copy if it’s not in your working directory):

1. Use $ to extract the weight column into a vector
2. Use [] to extract the month column into a vector
3. Extract the hindfoot_length column into a vector using pull() and use this vector to calculate the mean hindfoot length ignoring null values

Expected outputs for Extracting vectors from data frames