DATA ANALYSIS > QUESTIONS & ANSWERS > OR&IE 3120 Industrial Data and System Analysis - Cornell University. HW 05 Solutions (All)

OR&IE 3120 Industrial Data and System Analysis - Cornell University. HW 05 Solutions

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OR&IE 3120 Industrial Data and System Analysis - Cornell University. HW 05 Solutions select STRFTIME('%Y-%m-%d %H:00:00', tpep_pickup_datetime) AS pickup_hour, COUNT(*) as num_trips from trips group ... by 1 order by 1 #2 SELECT z1.zone As PUZone, z2.zone AS DOZone, COUNT(*) as num_trips FROM trips INNER JOIN zone as z1 ON trips.PULocationID = z1.LocationID INNER JOIN zone as z2 ON trips.DOLocationID = z2.LocationID GROUP BY 1,2 ORDER BY 3 DESC LIMIT 10 #3. (a) P(D<=5) is the number of records with D<=5 divided by the total number of records. We can get the number of records where D<=5 by running this query SELECT COUNT(*) FROM Demand WHERE D<=5 The result is 78. There are 246 records in Demand. So P(D<=5) = 78/246 = .317073171 (b) Q01 SELECT N, COUNT(*) As NumRecordsWithDLessThanOrEqualToN FROM Demand, WholeNumbers WHERE D <= N GROUP BY N ORDER BY N (c) Q02 SELECT * FROM Q01 WHERE NumRecordsWithDLessThanOrEqualToN >= 0.5*246 ORDER BY N (d) Q03 SELECT * FROM Q02 ORDER BY N LIMIT 1 (e) SELECT N, COUNT(*) As NumRecordsWithDLessThanOrEqualToN FROM Demand, WholeNumbers [Show More]

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