Let's determine if Ross has been billed correctly for his purchase by calculating the total amount step-by-step. We'll include the cost of the items, the promotional discount, and the shipping charges.
1. Calculate the total cost of each type of item before any discounts:
[tex]\[
\text{Cost of 3 cookbooks} = 3 \times \$18.89 = \$56.67
\][/tex]
[tex]\[
\text{Cost of 1 set of measuring cups} = 1 \times \$2.68 = \$2.68
\][/tex]
[tex]\[
\text{Cost of 4 kitchen utensils} = 4 \times \$5.35 = \$21.40
\][/tex]
[tex]\[
\text{Cost of 1 cooling rack} = 1 \times \$9.60 = \$9.60
\][/tex]
2. Apply the promotional discount to the cookbooks if eligible:
Since Ross purchased 3 cookbooks, he is eligible for the [tex]$\$[/tex]5[tex]$ promotional discount.
\[
\text{Total cost for cookbooks after discount} = \$[/tex]56.67 - \[tex]$5 = \$[/tex]51.67
\]
3. Sum the costs for all items to calculate the subtotal:
[tex]\[
\text{Subtotal} = \$51.67 + \$2.68 + \$21.40 + \$9.60 = \$85.35
\][/tex]
4. Determine the shipping cost based on the subtotal:
Since the subtotal is [tex]$\$[/tex]85.35[tex]$, which falls in the range $[/tex]\[tex]$50$[/tex] up to [tex]$\$[/tex]100[tex]$, the standard shipping cost is $[/tex]\[tex]$5.25$[/tex].
5. Calculate the total billed amount including shipping:
[tex]\[
\text{Total billed amount} = \$85.35 + \$5.25 = \$90.60
\][/tex]
6. Compare the calculated total billed amount with the given billed amount:
Ross was billed [tex]$\$[/tex]94.35[tex]$. The calculated total is $[/tex]\[tex]$90.60$[/tex].
To determine if Ross was billed correctly, we find the difference:
[tex]\[
\text{Difference} = \$94.35 - \$90.60 = \$3.75
\][/tex]
The calculated total billed amount is [tex]$\$[/tex]90.60[tex]$, which is $[/tex]\[tex]$3.75$[/tex] less than what Ross was actually billed.
Therefore, the correct conclusion is:
b. Ross has not been charged enough for his purchase.
