Basic Array Arithmetic

Problem Statement

Perform basic arithmetic operations on NumPy arrays.

Background

NumPy supports element-wise arithmetic:

• arr + n: Add n to each element
• arr - n: Subtract n from each element
• arr * n: Multiply each element by n
• arr / n: Divide each element by n

Your Task

Write a function array_arithmetic(arr, n) that returns a dictionary with:

• "add": Array after adding n (as list)
• "subtract": Array after subtracting n (as list)
• "multiply": Array after multiplying by n (as list)
• "divide": Array after dividing by n (as list, rounded to 2 decimals)

Output Format

Return a dictionary with exactly these four keys.