Assume that the width dimension in a product is normally distributed. Considering normally distributed variables, two standard deviations away from the mean in both directions encompasses approximately what percent of all observations? a. 34 b. 68 c. 95 d. 99 The interquartile range a. includes the 1st quartile and the 4th quartile b. is inclusive of all observations between the 25th and the 75th percentiles c. covers approximately 68% of all observations d. spans from the 25th lowest score on a variable to the 25th from the highest score on a variable