I have a problem annoying me. I have associative word lists which were formed by 150 participant's answers to a given word. At the same time, I gathered information about each word's valance with a 5 point Likert type question which ranged from very negative to very positive and at the middle of the range there was neutral choice. Then I grouped these answers into 3 categories (negative, neutral, positive) and I've aggregated the data to percentages. For example, 74% of answers given to valence of words writing for Music list are positive, 16.8% are neutral and 9.3% are negative.
So the question begins here. How can I say these differences between percentages are statistically significant? Which test is appropriate?