3304.py

# Find median
median_score = marks['math score'].median()
# Extract its prob
median_prob = math_pmf[median_score]
# Find 25th percentile
percentile_25th = marks['math score'].describe()['25%']
# Extract its prob
percentile_prob = math_pmf[percentile_25th]

# Recreate the plot with annotations
fig, ax = plt.subplots(figsize=(12,6))
# Plot the PMF
math_pmf.plot()
# Labelling
ax.set(xlabel='Math Score',
       ylabel='Frequency',
       title='The Probabilty of Each Score Occuring Among Students')

# Annotate the median score
ax.annotate(text=f'Median Score: {int(median_score)}',
            xy=(median_score, median_prob),
            xycoords='data',
            fontsize=15,
            xytext=(-350, 50),
            textcoords='offset points', 
            arrowprops={'color': 'red'})

# Annotate the 25th percentile
ax.annotate(text=f'25th percentile: {int(percentile_25th)}',
            xy=(percentile_25th, percentile_prob),
            xycoords='data',
            fontsize=15,
            xytext=(-300, -75),
            textcoords='offset points', 
            arrowprops={'color': 'red'});