Rich purchased a vacant lot and started construction on a commercial building. Rich's current assessment ratio is ___________%.

In the context of property assessment in Arizona, the assessment ratio is crucial for determining property tax obligations. Each type of property has a specific assessment ratio that represents the percentage of market value used to calculate property taxes.

In this instance, commercial properties typically have an assessment ratio of 18% of the full cash value. Given that Rich is constructing a commercial building, it is appropriate that the current assessment ratio is represented as 15/18. This ratio indicates that 15% of the value is designated for assessment purposes. Specifically, an assessment ratio of 15/18 signifies that the property is being valued for tax purposes at a fraction of the full market value, which is consistent with commercial property valuations in Arizona.

Therefore, the answer that indicates a current assessment ratio of 15/18 accurately reflects the standard practice for assessing commercial properties in the state, encapsulating the ongoing value and responsibility Rich has regarding property taxation.