Instructions The Kamcord SDK (software development kit) is currently integrated in over 400 mobile games. A user playing one of these games may elect to record and share a gameplay video via Kamcord’s technology. The sharing process involves pulling up our UI screen, which enables the user to share to various social networks, watch other videos, and make a profile. One of the metrics we use to measure the performance of our SDK is Day7 UI retention. We define Day7 UI retention as the percent of users who reopen the Kamcord UI exactly 7 days after the date of their first Kamcord UI open. Note that whether a user reopens the Kamcord UI on Day 6 or Day 8 is irrelevant to this metric. For example, say we were looking to measure Day7 UI retention over the first two days of October 2014. Twenty users opened the Kamcord UI for the first time on 10/1. On 10/8, four of these twenty users reopened the UI. On 10/2, five users opened the Kamcord UI for the first time and two of these users reopened the UI on 10/9. The SDK’s Day7 UI retention from 10/1 to 10/2 would then be (4+2) / (20+5) = 24%. Attached is a csv file with sample SDK data from a subset of users who began using the SDK in September. The fields provided are: ● user_id ● event_name ○ Opening the Kamcord UI has event_name UI_OPEN_COUNT ● event_count ○ Represents the number of times an event occurred ● event_time ● os_name ● sdk_version We would like you to perform the following: 1. DesignamodelforthedatathatisdesignedtoallowausertoqueryforDay7UI retention over a day range, as well as allow for filtering on a specific OS name and SDK version. 2. Writeascriptthatreadsthedatafromthecsvfileintoyourmodel. 3. Useyourmodeltoanswerthefollowingquestions: a. WhatwastheoverallDay7UIRetentionoverthemonthofSeptember? b. WhatwastheDay7UIRetentionfromSeptember8throughSeptember 10 for the Android SDK?  c. What was the Day7 UI Retention over the month of September for version 1.7.5 of the iOS SDK?
