[Easy] findIndex

[Easy] square

[Easy] getAverage

[Easy] removeDuplicate

[Easy] Array.prototype.at

[Easy] Array.prototype.last

[Easy] Chunk Array

[Easy] Apply Transform Over Each Element in Array

[Easy] Filter Elements from Array

[Easy] Array Reduce Transformation

[Easy] Array Sort By

[Medium] consolidateData

[Medium] Event Emitter

[Medium] Flatten Deeply Nested Array

[Medium] Join Two Arrays by ID