University GPA by Major ANOVA

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

np.random.seed(1111)

# GPA (0-4.0)
engineering = np.random.normal(3.2, 0.4, 80)
business = np.random.normal(3.4, 0.35, 80)
sciences = np.random.normal(3.1, 0.45, 80)
humanities = np.random.normal(3.5, 0.32, 80)
arts = np.random.normal(3.6, 0.3, 80)

engineering = np.clip(engineering, 2.0, 4.0)
business = np.clip(business, 2.0, 4.0)
sciences = np.clip(sciences, 2.0, 4.0)
humanities = np.clip(humanities, 2.2, 4.0)
arts = np.clip(arts, 2.3, 4.0)

F_stat, p_value = stats.f_oneway(engineering, business, sciences, humanities, arts)

fig, ax = plt.subplots(figsize=(13, 7), facecolor='#ffffff')
ax.set_facecolor('#ffffff')

colors = ['#4927F5', '#F5B027', '#6CF527', '#F5276C', '#27D3F5']
data = [engineering, business, sciences, humanities, arts]

bp = ax.boxplot(data, positions=[1, 2, 3, 4, 5], widths=0.55, patch_artist=True,
                medianprops={'color': '#1f2937', 'linewidth': 2},
                whiskerprops={'color': '#9ca3af', 'linewidth': 1.5},
                capprops={'color': '#9ca3af', 'linewidth': 1.5},
                flierprops={'marker': 'o', 'markerfacecolor': '#d1d5db', 'markersize': 4})

for patch, color in zip(bp['boxes'], colors):
    patch.set_facecolor(color)
    patch.set_alpha(0.6)
    patch.set_edgecolor(color)
    patch.set_linewidth(2)

labels = ['Engineering', 'Business', 'Sciences', 'Humanities', 'Arts']

# Dean's list threshold
ax.axhline(y=3.5, color='#22c55e', linestyle='--', alpha=0.7, linewidth=1.5)
ax.text(5.45, 3.5, "Dean's List", fontsize=7, color='#22c55e', va='center')

# Enrollment and mean
enrollment = ['2,400', '3,100', '1,800', '1,200', '850']
for i, (d, enr, color) in enumerate(zip(data, enrollment, colors)):
    ax.text(i+1, 1.85, f'μ={d.mean():.2f} | n={enr}', ha='center', fontsize=8, color=color)

# Stats header
stats_text = f"ANOVA: F={F_stat:.2f}, p={p_value:.4f} | Highest GPA: Arts (μ={arts.mean():.2f})"
bbox = dict(boxstyle="round,pad=0.3", facecolor='#f8fafc', edgecolor='#27D3F5', lw=2)
ax.text(0.5, 1.02, stats_text, transform=ax.transAxes, fontsize=9, color='#1f2937',
        ha='center', va='bottom', fontfamily='monospace', bbox=bbox)

ax.set_xticks([1, 2, 3, 4, 5])
ax.set_xticklabels(labels, fontsize=10, color='#1f2937')
ax.set_ylabel('GPA (4.0 Scale)', fontsize=12, color='#1f2937', fontweight='500')
ax.set_title('Academic Performance by Major\nFall 2024 Semester', 
             fontsize=14, color='#1f2937', fontweight='bold', pad=25)

ax.tick_params(colors='#374151')
for spine in ax.spines.values():
    spine.set_color('#e5e7eb')
ax.yaxis.grid(True, color='#f3f4f6', linewidth=0.8)
ax.set_axisbelow(True)
ax.set_ylim(1.8, 4.1)

plt.tight_layout()
plt.show()