IQ is standardized to a population distribution. As such someone with an IQ of 120 is not 50% smarter than someone with an IQ of 80; rather, they simply have a 50% higher "score". But there is no standard zero-point on the IQ scale; the "IQ of a rock" could be anywhere from -5000 to +50 or so. That doesn't mean IQ is meaningless -- it correlates with a variety of positive outcomes -- but that low-IQ people are not "proportionally" less intelligent as measured by the IQ. Rather the IQ scale is set up to have a seemingly normal distribution relative to the observed distribution of fluid reasoning in the human population. The standard deviation of IQs is arbitrarily set at 15, and the mean is set at 100. We could easily reform the IQ scale to have a mean of 1000 and a sigma of 1, or a mean of zero and a sigma of 100. The number, itself, is meaningless without context.

There is no evidence that a person with low IQ cannot accomplish the the tasks involved in e.g. software engineering, although they would probably do so more slowly than a person with high IQ. From Wiki:

"The prevailing view among academics is that it is largely through the quicker acquisition of job-relevant knowledge that higher IQ mediates job performance. "

Also, going to college has no effect on IQ, so "college-level IQ" is meaningless gobbledygook.