A boot camp sergeant recorded the number of attempts each of 20...

1. A boot camp sergeant recorded the number of attempts each of 20 soldiers required to complete an obstacle course. The results were

2, 5, 3, 1, 2, 7, 1, 4, 2, 4, 
8, 1, 3, 2, 6, 5, 2, 4, 3, 1. 

Create a simple frequency table to display these data. Add columns for cf, rf, crf, and cpf. (Note: Because lower numbers reflect better scores, you may want to put the lowest number on top of the table.)

1. What proportion of the soldiers completed the course on the first attempt?
   1. The proportion of soldiers that could complete the course on the first attempt is 0.2.
2. What proportion of them needed four or more attempts?
   1. The portion of them that needed four or more attempts is 40%
3. What is the percentile rank of someone who needed five attempts?
   1. The percentile rank of someone who needed five attempts
4. What score is closest to being the third quartile?
   1. 85%
5. Draw a frequency polygon to represent the data.
   1. 
      
       
6. Draw a cumulative percentage polygon (ogive) to represent the data in Exercise 3.
   
   Use your graph to answer the following questions (approximate your answer to the nearest tenth of a point):
   1. What score is at the 30th percentile?
   2. What score is at the 50th percentile?
   3. What is the percentile rank that corresponds to a score of 3.5?
   4. What is the percentile rank that corresponds to a score of 6.5?