input: Write a python function to calculate equilibrium price from a dictionary of prices.
  assert calculate_equilibrium_price({"store1": 100, "store2": 150, "store3": 200}) == 150.0
  assert calculate_equilibrium_price({"storeA": 120, "storeB": 180}) == 150.0
  assert calculate_equilibrium_price({"shop1": 80, "shop2": 100, "shop3": 120}) == 100.0
output: def calculate_equilibrium_price(prices):
      return sum(prices.values()) / len(prices)