Area under Normal curve with +-1 SD:

Ans. a. 0.68 (Ref Park 23/e p849, 21/e p788; Simple Biostatics by Indrayan and Indrayan Central Tendency in Various Distribution/111: Park 23/e p849, 22/e p849.22/e p792) Area under Normal curve with +- 1 SD is 0.68.In Normal Distributionm +- = 68.3%Qm +- 2 = 95.4% Qm +- 3 = 99.7%QDistributionCentral TendencyNormal (Gaussian) DistributionMean = Median = ModeQRight (Positive) Skew DistributionMean > Median > ModeQLeft (Negative) Skew DistributionMean < Median < ModeQ In Distribution with Extreme Values (Outliers)Most affected measure of central tendencyMeanLeast affected measure of central tendencyModeMost preferable measure of central tendencyMedian