For Each Analytical Procedure Listed Below, Identify a Potential Misstatement

For each analytical procedure listed below, identify a potential misstatement in the property management accounts it could help find.
a. Compute the ratio of depreciation expense to the related property, plant, and equipment accounts and compare to prior years' ratios.
b. Compare monthly or annual repairs and maintenance with previous years.
c. Compute ratio of insurance expense to the related property, plant, and equipment accounts and compare to prior years' ratios.