When datacomp corp., a producer of software, delayed the introduction of its new spreadsheet app to modify the package, its scheduled tv advertisements announcing the new product needed to be revised. in this case, a change in the variable caused changes in the variable of the marketing mix?

In this case, a change in the "product" variable caused changes in the "promotion" variable of the marketing mix.

Marketing mix is tied in with putting the correct item or a mix thereof in the place, at the perfect time, and at the correct cost. The troublesome part is doing this well, as you have to know each part of your marketable strategy.  

An product is a thing that is constructed or created to fulfill the necessities of a specific gathering of individuals. The product can be immaterial or unmistakable as it very well may be as administrations or merchandise.  

Promotion is an imperative part of marketing as it can help mark acknowledgment and deals.