Fraction of sky covered Time of day Midn. 3AM 6AM 9AM Noon 3PM 6PM 9P.M 0.39 0.41 0.38 0.45 0.48 0.47 0.45 0.41 0.52 0.49 0.57 0.55 0.53 0.46 0.46 0.55 0.52 0.62 0.60 0.57 0.49 0.43 20.7 0.52 0.56 0.54 0.64 0.63 0.59 0.52 0.47 20.6 0.54 0.66 0.65 0.61 0.54 0.49 0.59 0.57 0.59 0.59 0.69 0.67 0.64 0.55 0.51 20.5 0.55 20.4 0.56 0.59 0.62 0.72 0.68 0.66 0.58 0.56 20.3 0.58 0.62 0.64 0.74 0.71 0.69 0.60 0.60 20.2 0.60 0.67 0.66 0.78 0.74 0.71 0.62 0.62 20.1 0.66 0.71 0.72 0.89 0.86 0.84 0.79 0.66 (a) What percentage of time is at least half of the sky covered by clouds at 3 A.M.? 59 % 1.0 20.9 0.48 20.8 0.50 (b) In order to model the frequency of an overcast sky, given the time of day, which variable must be held constant? fraction of sky covered row ◆ time of day column (c) Is the cross section in part (b) represented by a row or a column of the table? X