You will be given a dataframe with three columns: student_id, base, and bonus. You should calculate the bonus_percentage column, which contains the percentage of each student's bonus relative to their base grade. The result should be sorted in ascending

order by the bonus_percentage column. Here's how you can do it in Python:

import pandas as pd

# create the dataframe with sample data
data = {'student_id': [1, 2, 3, 4], 'base': [80, 90, 85, 75], 'bonus': [10, 5, 15, 8]}
df = pd.DataFrame(data)

# calculate the bonus_percentage column
df['bonus_percentage'] = df['bonus'] / df['base'] * 100

# sort the dataframe by bonus_percentage in ascending order
df = df.sort_values(by=['bonus_percentage'], ascending=True)

# print the final dataframe
print(df)

This will output:

   student_id  base  bonus  bonus_percentage
1           2    90      5          5.555556
3           4    75      8         10.666667
0           1    80     10         12.500000
2           3    85     15         17.647059

Note that the `bonus_percentage` column is calculated by dividing the `bonus` column by the `base` column and multiplying the result by 100. The resulting dataframe is then sorted by the `bonus_percentage` column in ascending order.