# Stats HW 5 - Alek Johnson A02275958 Stats HW 5 2.78 a b c...

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Alek Johnson A02275958 Stats HW 5 2.78 a) b) c) 2.79 a) y= -0.126 + 0.061x b) y= -0.126 + 0.061x = -0.126 + 0.061(2.0) y= -.004 Up and over method shows that 2.0 social distress is about 0 brain activity.
c) r = 0.878 r^2 = .770 77% of the variance in brain activity can be explained by changes in social distress. 2.80 y = -2.3947712 + 0.15848297x is the rate at which icicles grow in cm/min for group 8903. y = -1.4532609 + 0.091126087x is the rate at which icicles grow in cm/min for group 8905. Flow rate affects growth tremendously. The growth rates are .158x and .091x. The faster the water flows, the more slowly the icicles grow. 2.81 Run 8903 x is time y is length Mean Time= 95 S.D. Time= 53.39 Mean of Lengths= 12.661 S.D. Lengths = 8.497 Correlation = 0.996 y=b0 + b1x b1=r(sy/sx) =.996 (8.497/53.39) = .158 b0= y - b1x =12.611-.158(95) = -2.399 y= -2.399 + .158x This matches the previous problems equation. Run 8903 Mean Time= 95 S.D. Time= 53.39 Mean of Lengths= 12.661 S.D. Lengths = 8.497 Correlation = 0.996 x=b0 + b1y b1=r(sx/sy) =.996 (53.39/8.497) = 6.258 b0= y - b1x =95 - 6.258(12.661) = 15.767 x= 15.767 + 6.258y The units that each of these slopes has is cm/min for predicting length from time and min/cm for predicting time from length.
2.102 a)