Assume that the differences are normally distributed. Complete parts (a) through (d) below. Observation 1 2 3 4 5 6 7 8 Upper X Subscript i 43.1 50.8 48.8 44.4 42.4 51.9 42.2 53.7 Upper Y Subscript i 45.5 52.6 51.9 48.7 45.3 53.5 46.1 53.5 Question content area bottom Part 1 (a) Determine d Subscript i Baseline equals Upper X Subscript i Baseline minus Upper Y Subscript i for each pair of data.