def f_to_c(f):
    """Convert Fahrenheit to Celsius and return a formatted string.

    Formula: C = (F - 32) * 5 / 9

    The Celsius value should be formatted with 1 decimal place.
    Convert the Fahrenheit input with float() so output is consistent.

    f_to_c(32)    -> "32.0°F = 0.0°C"
    f_to_c(212)   -> "212.0°F = 100.0°C"
    f_to_c(98.6)  -> "98.6°F = 37.0°C"
    """
    pass