Final answer:
To accurately answer the question, we need the specific data of the population of each county in California in 2010.
Step-by-step explanation:
To find the number of counties in California with a population of more than 50,000 but less than 100,000 in 2010, we need to refer to the relevant data. We'll assume the data includes the population of each county in California. We can then analyze this data and count the number of counties that meet the criteria. If there is no access to the specific data, we cannot accurately answer the question. Please provide the necessary data for a precise answer.