8.45 hours. To use Chebyshev's theorem, we must first determine how many standard deviations above and below the mean 8.45 and 3.95 are, respectively. use the following formula. z=standarddeviationvaluehigherthanthemeanmean Find z for the upper value. z=standarddeviationvaluehigherthanthemeanmean=1.58.45= the following formula. z=standarddeviationmeanvaluelowerthanthemean Find z for the lower value. z=standarddeviationmeanvaluelowerthanthemean=1.56.2 part. (a) What percentage of regular grade gasoline sold between $2.64 and $4.24 per gallon? (b) What percentage of regular grade gasoline sold between $2.64 and $3.84 per gallon? (c) What percentage of regular grade gasoline sold for more than $3.84 per gallon? structure is $3,400. Assume that the standard deviation is $1,400. (a) What is the z-score for a backyard structure costing $2,400 ? (Round your answer to two decimal places.) z= (b) What is the z-score for a backyard structure costing $5,500 ? z= (c) Interpret the z-scores in parts (a) and (b). Comment on whether either should be considered an outlier. (d) The cost for a backyard shed-office combination built in Albany, California, is $13,550. Compute the z-score for this structure. z= Should this structure be considered an outlier? Explain. This structure is because the z-score is