Assume that the differences are normally distributed. Complete parts (a) through (d) below. Observation 1 2 3 4 5 6 7 8 51.7 46.8 44.2 41.5 43.9 48.0 48.6 46.9 Y 52.2 47.3 45.8 46.7 45.4 48.2 49.9 48.1 (a) Determine d, = X - Y, for each pair of data. O Observation 2 4 5 6 8 di -.5 - .5 - 1.6 - 5.2 - 1.5 - .2 - 1.3 -1.2 (Type integers or decimals.) (b) Compute d and sd d= -1.5 (Round to three decimal places as needed.) S. = (Round to three decimal places as needed.)