Consider version I of the cost minimisation problems below.

With the technology in place, the minimum cost $(C^{***})$ at which the level of output below can be achieved is:

$($Instruction: Type in the value of $C^{**}$ in the cell below using two decimal places. Do NOT use alphabetical characters, symbols such as $ or commas as thousand separators.

Example: $"1000\mathrm{.}00"$ is a valid entry, but $"C^{***}=$$$1,{000\mathrm{.}000}^{?}$ is not a valid numerical entry.$)$