A competitive cost of living can be a key advantage for states that want to attract workers and keep them. If the cost of living is reasonable, workers will be able to afford housing, food, health care and transportation. Their wages will go further and they will enjoy a higher standard of living.

Minnesota generally ranks in the middle of most state-by-state comparisons of cost of living. That was the case when CNBC examined cost of living (along with nine other criteria) in determining the Top State for Business 2015. The business channel rated Minnesota 32nd in the cost-of-living category, with Mississippi and Tennessee grabbing the No. 1 and No. 2 spots, respectively.

The Missouri Economic Research and Information Center conducts a quarterly national survey that looks at six cost-of-living categories for all 50 states. In its 2015 first quarter study, Minnesota costs were below the national average in three of those categories - housing, utilities and transportation.

Utilities, in particular, were a strong point for the state. Minnesota had the fifth-lowest costs in the country for utilities (heating, electricity, water, sewer, garbage), according to the survey.

Clothing is another cost-of-living feature that stands out in Minnesota. Clothing costs are cheaper in Minnesota because the state doesn't apply sales tax to apparel and shoes.

Another factor working in Minnesota's favor is the state's relatively high household incomes. The median annual household income in Minnesota in 2014 was $61,814, which ranked ninth nationally and was easily the highest in the Midwest. The next-closest Midwestern state was Illinois, with a median household income of $53,234 a year.

The Twin Cities, in particular, rates high for median household incomes. In a comparison of 280 U.S. metropolitan areas, the U.S. Census Bureau found that Minneapolis-St. Paul had the fifth-highest median household income in the country.

Cost of living was just one of 10 categories that CNBC used in naming Minnesota the top state for business. We've been looking closer at each of those categories to get a better idea of why the state came out on top in the 2015 rankings. Go here to see more of our blog posts on this topic.