Jocelyn's total cost for four red oak trees, including the promotion and tax, is approximately $1,604.23.
To calculate the total cost for Jocelyn's purchase of four red oak trees with the promotion and tax included, we can follow these steps:
1. Determine the cost of three red oak trees at the regular price.
2. Calculate the discounted price for the fourth red oak tree.
3. Find the total cost for all four red oak trees before tax.
4. Add the tax to get the final total cost.
Let's break it down:
1. Cost of three red oak trees at the regular price:
![\[3 * \text{Regular Price} = 3 * $390.00\]](https://img.qammunity.org/2024/formulas/mathematics/high-school/z8jc6p8ovaumofdgtiv7txwrs3he509pde.png)
2. Discounted price for the fourth red oak tree:
![\[80\% \text{ off regular price} = 0.80 * $390.00\]](https://img.qammunity.org/2024/formulas/mathematics/high-school/vefl48g7cq43jmtz8bj6o6wtosrbxvp03s.png)
3. Total cost for all four red oak trees before tax:
![\[\text{Total cost} = \text{Cost of three trees} + \text{Discounted price for the fourth tree}\]](https://img.qammunity.org/2024/formulas/mathematics/high-school/yzqrmsna8u2i9ixaza16k6ssajsdx0t75n.png)
4. Add the tax to the total cost:
![\[\text{Total cost with tax} = \text{Total cost} + \text{Tax}\]](https://img.qammunity.org/2024/formulas/mathematics/high-school/9u5yfqo4w5oqos4orpzu6qokaipqztsuod.png)
Let's calculate each step:
1. Cost of three red oak trees at the regular price:
![\[3 * $390.00 = $1,170.00\]](https://img.qammunity.org/2024/formulas/mathematics/high-school/3v4q99khf53995l0l2n7v4cghrmpekvss4.png)
2. Discounted price for the fourth red oak tree:
![\[0.80 * $390.00 = $312.00\]](https://img.qammunity.org/2024/formulas/mathematics/high-school/l7lrugky2pa46m46vsvw7dhbwlt9ovufm4.png)
3. Total cost for all four red oak trees before tax:
![\[$1,170.00 + $312.00 = $1,482.00\]](https://img.qammunity.org/2024/formulas/mathematics/high-school/i8x1zdi1qmv7gy1inugfp95vjxqy65ftp0.png)
4. Add the tax:
![\[\text{Tax} = 8.25\% \text{ of } $1,482.00\]](https://img.qammunity.org/2024/formulas/mathematics/high-school/fz9bmohb7nyjyh0u8nw2rnhamsrmwrzmb6.png)
![\[\text{Tax} = 0.0825 * $1,482.00\]](https://img.qammunity.org/2024/formulas/mathematics/high-school/qjox2bba4b71oxu4k0dr6juk5sno54y0np.png)
Now, calculate the tax:
![\[\text{Tax} \approx $122.23\]](https://img.qammunity.org/2024/formulas/mathematics/high-school/2obfgrm3snz69qy5ophhpyvsvewj63v8bj.png)
Finally, add the tax to the total cost:
![\[\text{Total cost with tax} = $1,482.00 + $122.23\]](https://img.qammunity.org/2024/formulas/mathematics/high-school/uyo9mul59pki6qkq1gh2y4e26x272b5vns.png)
Therefore, Jocelyn's total cost for four red oak trees, including the promotion and tax, is approximately $1,604.23.