For each of the variables described below, indicate whether it is a quantitative or a categorical (qualitative) variable. Also, indicate the level of measurement for the variable: nominal, ordinal, interval, or ratio. Make sure your responses are the most specific possible. Type of Level of Variable variable measurement X 5 ? O Nominal (a) Total elapsed time (in seconds) for O Quantitative O Ordinal completion of an assembly line O Interval operation O Categorical O Ratio O Nominal O Quantitative O Ordinal (b) Letter grade (A, B, C, D, or F) O Interval O Categorical O Ratio O Nominal O Quantitative O Ordinal (c) Temperature (in degrees Celsius) O Interval O Categorical O Ratio