Delivery Time Distribution

import matplotlib.pyplot as plt
import numpy as np
from scipy import stats

np.random.seed(107)

express = np.random.gamma(2, 0.5, 400)
standard = np.random.gamma(3, 1.5, 500)
economy = np.random.gamma(4, 2, 300)

fig, ax = plt.subplots(figsize=(12, 6), facecolor='#ffffff')
ax.set_facecolor('#ffffff')

x = np.linspace(0, 20, 500)

methods = [
    (express, 'Express', '#27F5B0'),
    (standard, 'Standard', '#F5B027'),
    (economy, 'Economy', '#F5276C'),
]

for data, label, color in methods:
    kde = stats.gaussian_kde(data)
    y = kde(x)
    mean_val = np.mean(data)
    ax.fill_between(x, y, alpha=0.3, color=color)
    ax.plot(x, y, color=color, linewidth=2.5, label=label + ' (' + str(round(mean_val, 1)) + ' days)')

ax.set_xlabel('Delivery Time (days)', fontsize=12, color='#1f2937', fontweight='500')
ax.set_ylabel('Density', fontsize=12, color='#1f2937', fontweight='500')
ax.set_title('Delivery Time by Shipping Method', fontsize=16, color='#1f2937', fontweight='bold', pad=15)

ax.tick_params(colors='#374151', labelsize=10)
for spine in ax.spines.values():
    spine.set_color('#d1d5db')
ax.legend(loc='upper right', facecolor='#f9fafb', edgecolor='#d1d5db', labelcolor='#374151')
ax.grid(True, alpha=0.3, color='#e5e7eb')
ax.set_xlim(0, 20)

plt.tight_layout()
plt.show()