hello please solve question 3 and 4 depend on 3

Returns the arithmetic mean of individual values in the tree information.

3- Insert the key 90 in the following heap tree: 60 15 35 12 10 20 18 4- Define the data structure of a binary tree containing integer values and then write a JAVA method calculate().which returns the average of the contents of all nodes (which contain odd numbers ) in a binary tree Recursion] ( ( .)