The frequency table below summarizes the total percentage of children under age 5 who were underweight in 2012, based on World Health Organization standards. This data set includes 36 countries. Percentage Underweight Frequency 0.0 - 5.9 16 6.0 - 11.9 6 12.0 - 17.9 6 18.0 - 23.9 3 24.0 - 29.9 3 30.0 - 35.9 2 Use the frequency table to answer the following questions. 

1. What is the class width of this frequency distribution? 

2. Find the lower class limit of the fourth interval. 

3. Find the class midpoint of the first interval. Do not round. 

4. Find the relative frequency of the third interval. Write as a percentage rounded to one decimal place. (Include the percentage symbol in your answer)