Wayne and celia had been married for 24 years before wayne died in an accident in 2014 . celia and her son, wally, age 21 in 2014 , continued to live at home in 2014 , 2015 , 2016 , and 2017 . wally worked part-time (earning $5,000 in each of the four years) and attended the university on a part-time basis. celia provided more than 50% of wally's support for all four years. what is celia's filing status for 2014 , 2015 , 2016 , and 2017 ?

Penny poodle wanted to know which dog obedience training program was more effective: puppy pride, the approach she has been using for any years, or doggie do-right, a new approach. penny convinced 50 human companions of untrained dogs to participate in her study. the dogs and their humans were randomly assigned to complete the puppy pride or doggie do-right course. at the end of the training programs, all of the dogs were scored on their level of obedience on a standardized dog obedience checklist (scores could range from 10 to 100). the design of this study is: