Soal No. 1 r (x,y) = N ( ∑ XY ) −( ∑ X ) ( ∑ Y ) √ ¿¿¿ r (x,y) = 30 ( 256 )−( 18 ) ( 321 ) √ { ( 30.18 – ( 18 ) 2 ) 30.( 4519)−( 321 ) 2 ¿ } r (x,y) = 7680−5778 √ ¿¿¿ r (x,y) = 1902 √ {( 240 )( 32529 ) } r (x,y) = 1902 √ 7026264 r (x,y) = 1902 2650 , 7 r (x,y) = 0,718 (Valid) r 11 = 2 ×r 1 / 21 / 2 ( 1+r 1 / 21/ 2 ) = 2 × 0 , 718 1 +0 , 718 = 1,435 1 , 718 = 0,836 (Reliabilitas) No X Y X² Y² XY 1 1 14 1 196 14 2 0 8 0 64 0 3 1 15 1 225 15 4 0 6 0 36 0 5 0 3 0 9 0 6 1 20 1 400 20 7 0 1 0 1 0 8 1 17 1 289 17 9 0 2 0 4 0 10 1 10 1 100 10 11 0 7 0 49 0 12 1 17 1 289 17 13 0 10 0 100 0 14 1 15 1 225 15 15 1 17 1 289 17 16 1 20 1 400 20 17 1 4 1 16 4 18 1 17 1 289 17 19 0 9 0 81 0 20 1 6 1 36 6 21 1 13 1 169 13 22 0 2 0 4 0 23 1 9 1 81 9 24 0 7 0 49 0 25 0 3 0 9 0 26 1 19 1 361 19 27 1 19 1 361 19 28 1 7 1 49 7 29 0 7 0 49 0 30 1 17 1 289 17 ∑ 18 321 18 451 9 256