Can you help me with these problems and explain step by step Cuz i have no clue how to do them

Find an equation (in term of x) of line through the points (-1,3) and (1,4)

(98 points) i need with 5 questions. answer definitions are welcomed, but not necessary.

The american academy of pediatrics wants to conduct a survey of recently graduated family practitioners to assess why they did not choose pediatrics for their specialization. provide a definition of the population, suggest a sampling frame, and indicate the appropriate sampling unit.