Answer:
 1) 20 stars; 30 points.
 2) 28 stars, 42 points.
 3) 38 stars, 57 points.
Step-by-step explanation:
<h3>
 The missing table is attached.</h3>
 
 Let  be "x" the numbers of stars Roberto collects and "y" his total points.
 The proportional relationship has this form:
 
 Where "k" is the constant of proportionality.
 We can choose the point  ) from the table, where:
) from the table, where:
 
 Substituting these values into   and solving for "k", we get:
 and solving for "k", we get:
   
 
 Knowing the value of "k", we determine that the  following Numbers of stars and the Total points could be used as the missing values in the table:
 1) For  :
 :
 
 2) For  :
 :
 
 3) For  :
 :
 