code: def fit_at(type, slope: nil, intercept: nil, n: nil)
        raise ArgumentError, "Incorrect input size: #{n}" unless n > 0
  
        case type
        when :logarithmic, :log
          intercept + slope * Math.log(n)
        when :linear
          intercept + slope * n
        when :power
          intercept * (n ** slope)
        when :exponential, :exp
          intercept * (slope ** n)
        else
          raise ArgumentError, "Unknown fit type: #{type}"
        end
      end
docs: Take a fit and estimate behaviour at input size n
  
   @example
     fit_at(:power, slope: 1.5, intercept: 2, n: 10)
  
   @return
     fit model value for input n
  
   @api public