I am currently in a public university (top 50 nationally, top 10 among public schools) for undergrad (3rd year), double majoring in operations research and economics. The past quarter I took 5 major courses because two of them were easy, and I ended up with 3 A's, an A- and a C. The C is a core math upper level course (real analysis serial B, about Riemann integral and Jordan regions) and the reason that I got the C is because of the professor's harsh policy that nearly 80% of students received C or worse grades. I planned to apply for master programs next year, and I am not pretty sure is that C a big problem to me? I am interested in master programs like applied economics, business analytics or finance. My GPA overall now is 3.43 with operations research overall 3.2 and Econ 3.6. This is the first C on my transcript. Thanks!
The short answer is "yes". However, depending on the school you're applying at, they may use a holistic approach to your application, meaning the C could have a small negative impact. However, if it came down between you and another candidate and you're the one that has the C, the other candidate will most likely get accepted.