---
title: "Chap 2第17题_对数正态分布的累计分布函数"
author: "Yuan Zhuang"
date: "2023-11-10"
documentclass: ctexart
output:
  rticles::ctex:
    fig_caption: yes
    number_sections: yes
    toc: yes
    keep_tex: true
---
# 1. 方法一：直接使用Lognormal的内置函数
```{r}
plnorm(400, meanlog = 5.75, sdlog = 0.4, lower.tail = FALSE)
```

# 2. 方法二：使用Lognormal和Normal之间的关系

```{r}
1 - pnorm(log(400),mean = 5.75, sd = 0.4)
```

或

```{r}
1 - pnorm((log(400)-5.75)/0.4)
```

