For the problem below create a set of $3$NF normalized relations $($or tables$)$ given the sample data$/$form below. Do not draw a dependency diagram; only the relational schema is needed.

$$ Start with a single table $($could be in NNF$)$ and then proceed to $1$NF $($no multi$-$valued attributes and has good PK$).$

$$ In the $1$NF relations, determine all the dependencies.

i$.$ Proceed with $2$NF and $3$NF

Determine the dependencies at each step.

ii$.$ Or determine the dependencies in the $1$NF table using A$->$B notation and write out all the tables in $3$NF$.$

$$ No need to draw and ERD, use the relational schema format:

i$.3$NF TABLE$\_$NAME $($Attribute$1,$ Attribute$2,.....)$ underline the PK$.$

$$ State clearly any $($reasonable$)$ assumptions you may make.

Problem $1$ business rules

Business Rules:

$$ The tax rate is based on the customer$$s state.

$$ All subtotals, the tax amount, and the invoice total are computed.

Problem $2$

$$ The bill is issued a few days $($not a set number of days$)$ after the discharge date.

$$ Each charged item belongs to a specific cost center.

$$ Each item belongs in a single cost center.

$$ All subtotals and the balance due are computed.