The manufacturing cost must be approximately $0.625 for the product to sell in stores for $1.75.
How did we get the value?
Let's denote the manufacturing cost as
. The manufacturer makes a 100% profit on this cost, so the selling price to the store is

The product is sold in stores for 40% more than the wholesale price, so the selling price in stores is

We are given that the product sells in stores for $1.75, so we can set up the equation:
![\[2.8C = 1.75\]](https://img.qammunity.org/2024/formulas/mathematics/college/pgckw24n7fi6nhksem98zku40swh28z7g3.png)
Now, solve for
:
![\[C = (1.75)/(2.8)\]](https://img.qammunity.org/2024/formulas/mathematics/college/lkggmb59s6s70ualc5x2ed8hp2huuhoz6n.png)
![\[C \approx 0.625\]](https://img.qammunity.org/2024/formulas/mathematics/college/ffa3y903sss8aoc87iutsp3pxsw72oyzgb.png)
So, the manufacturing cost must be approximately $0.625 for the product to sell in stores for $1.75.