正态分布概率计算

def solve():
    import matplotlib.pyplot as plt
    import numpy as np
    from scipy import stats
    mu, sigma = 70, 10
    prob = stats.norm.cdf(80, mu, sigma) - stats.norm.cdf(60, mu, sigma)
    print(f"成绩在60-80分之间的概率: {prob:.4f}")
    x = np.linspace(30, 110, 1000)
    pdf = stats.norm.pdf(x, mu, sigma)
    plt.figure(figsize=(10, 6))
    plt.plot(x, pdf, 'b-', linewidth=2)
    x_fill = x[(x>=60) & (x<=80)]
    plt.fill_between(x_fill, stats.norm.pdf(x_fill, mu, sigma), alpha=0.3, color='red', label=f'P(60≤X≤80)={prob:.4f}')
    plt.xlabel('成绩')
    plt.ylabel('概率密度')
    plt.title(f'正态分布 N({mu}, {sigma}²)')
    plt.legend()
    plt.grid(alpha=0.3)
    plt.show()