To find the sales tax on a $930 item, we first need to determine the sales tax rate based on the information provided for the $600 item.
We know that the sales tax \( T \) can be expressed as: \[ T = k \cdot C \] where \( k \) is the sales tax rate and \( C \) is the cost of the item.
Given that the tax on a $600 item is $42, we can set up the equation: \[ 42 = k \cdot 600 \]
Now, we can solve for \( k \): \[ k = \frac{42}{600} = 0.07 \]
This means the sales tax rate is 7%.
Next, we calculate the sales tax on a $930 item using the same rate: \[ T = k \cdot C = 0.07 \cdot 930 \]
Calculating this gives: \[ T = 0.07 \cdot 930 = 65.1 \]
Therefore, the sales tax on a $930 item is $65.10.