applied data science capstone coursera week 2 quiz answers
Check Points: Exploratory Analysis Using SQL
1. Have you loaded the SQL extension and establish a connection with the SQLIte database ?
- Yes
- No
Exploratory Data Analysis using SQL
4. Which of the following will retrieve upto 20 records from the spacex table?
- SELECT TOP 20 rows from SPACEXTBL
- SELECT * from SPACEXTBL MAX 20
- SELECT * from SPACEXTBL where count(*)=20
- SELECT * from SPACEXTBL LIMIT 20
5. Which of the following queries display the minimum payload mass?
- select payload_mass__kg_ from SPACEXTBL order by payload_mass__kg_ desc LIMIT 1
- select min(payload_mass__kg_) from SPACEXTBL
- select payload_mass__kg_ from SPACEXTBL order by payload_mass__kg_ group by booster_version LIMIT 1
- select payload_mass__kg_ from SPACEXTBL where payload_mass__kg_=(select max(payload_mass__kg_) from SPACEXTBL) LIMIT 1
6. You are writing a query that will give you the total payload_mass_kg carried by the booster versions. The mass should be stored in the mass column. You want the result column to be called “Total_Payload_Mass”. Which of the following SQL queries is correct?
- SELECT sum(PAYLOAD_MASS__KG_) from SPACEXTBL
- SELECT sum(PAYLOAD_MASS__KG_) as Total_Payload_Mass from SPACEXTBL
- SELECT count(PAYLOAD_MASS__KG_) as Total_Payload_Mass from SPACEXTBL
7. Which of the following query is used to display the mission outcome counts for each launch site?
- select count(“Mission_Outcome”) as MISSION_OUTCOME_COUNT,Launch_Site from SPACEXTBL group by “Launch_Site”;
- select sum(“Mission_Outcome”) as MISSION_OUTCOME_COUNT,Launch_Site from SPACEXTBL group by “Launch_Site”;
8. What are the unique launch sites mentioned in the Spacex table?
- None of the Above
- CCAS LC-40,KSC LC-39A,VAFB SLC-4E , CCAFS SLC-80
- CCAFS LC-40,KSC LC-39B,VAFB SLC-4k , CCAFS SLC-40
- CCAFS LC-40,KSC LC-39A, VAFB SLC-4E , CCAFS SLC-40
