每日一练 | Data Scientist & Business Analyst 面试题 170

大数据应用 · 公众号 · 大数据 · 2017-08-24 09:57

正文

从6月15日起，数据应用学院将与你一起温习数据科学（DS）和商业分析（BA）领域常见的面试问题。希望积极寻求相关领域工作的你每天关注我们的问题并且与我们一起思考，我们将会在第二天给出答案。

Day 70

DS Interview Questions

What is the Central Limit Theorem? Explain it. Why is it important?

BA Interview Questions

SQL: Query all columns for all American cities in CITY with populations larger than 100000. The CountryCode for America is USA.
The CITY table is described as follows:

欲知答案如何？请见下期分解！

Day 69 答案揭晓

DS Interview Questions

What is the difference between Cluster and Systematic Sampling?

Cluster sampling is a technique used when it becomes difficult to study the target population spread across a wide area and simple random sampling cannot be applied. Cluster Sample is a probability sample where each sampling unit is a collection, or cluster of elements. Systematic sampling is a statistical technique where elements are selected from an ordered sampling frame. In systematic sampling, the list is progressed in a circular manner so once you reach the end of the list,it is progressed from the top again. The best example for systematic sampling is equal probability method.

BA Interview Questions

What is Engaged and Not Engaged in digital marketing?

Engaged vs not engaged will be a unique threshold for each individual business. In this metric, the engagement threshold can be defined as Average Time on Site or Pages per Visit. Both measures provide a strong indication for the quality of a visit. Digital marketers may also want to track a metric like goal completion rate.