can someone explain how to find the significant main effects and what info to use with the bar charts? Would appreciate an example

Researchers wanted to test if a person's marital status and if they are a parent influences the hours of sleep they get per night. Below are 3 tables from different set of participants. For each of the following tables: 1) Decide if there are significant main effects of factors 1 (married) and/or 2 (parent) 2) Decide if there is a significant interaction. 3) Draw 2 different bar charts. Question 4) Married Single Parent 6 4.5 Not A Parent 7.5 4.5 Question 5) Married Single Parent 6.75 6.25 Not A Parent 7.25 7.75 Question 6) Married Single Parent 7.5 5.5 Not A Parent 7.75 8.0