Walter & co. has recently placed their new product in 1650 stores. those stores have a sales dollar total volume of $1.3 billion. their industry research reveals that there are 6400 stores with dollar volume of $8.4 billion that could possibly carry products such as their product. the new alter & co. product is an electronic device where total retail stores carrying these devices total 1,920 selling $850 million of these devices. alter & co. estimates that $51 million of this type of device are sold in the 1650 stores where their brand can be found. what is the product category volume of walter & co. distribution?