# Lognormal transformation by the CDF method

> ML preparation item.

- Stable ID: `harvard-stat110-f2011-sp5-continuous-q1`
- Area: Mathematics
- Topic: Probability
- Origin: external
- Expected time: 12 minutes
- Skills: change-of-variables, cdf-method, lognormal-distribution
- Item JSON: https://mlprep.iwase.dev/data/items/harvard-stat110-f2011-sp5-continuous-q1.json

This site does not reproduce the third-party problem.

- Source: Harvard Stat 110 Probability — Strategic Practice
- Document: Strategic Practice and Homework 5
- Locator: Section 3: Continuous Distributions, Problem 1, page 2
- Original problem: https://stat110.hsites.harvard.edu/resource/strategic-practice-and-homework-5
- Official answer: https://stat110.hsites.harvard.edu/resource/strategic-practice-and-homework-5
- Answer status: official-solution


## Tutoring contract

Ask for the learner's attempt, begin with the smallest useful hint, preserve item ID `harvard-stat110-f2011-sp5-continuous-q1`, and record a real attempt with `recorded_by: "agent"` and `agent_session_id` when available using https://mlprep.iwase.dev/schema/attempt-record.json.