Answer:
frictional unemployment rate = 4%
Explanation:
Ito, Jack, and Kelley fall under structural unemployment, meaning that they are unemployed because their skills do not match the requirements for current job openings.
Every month, other 4 people lose their jobs, but then find a new job next month (first Amy, Barbara, Carine, and Denise, then Evan, Francesco, George, and Horatio, and then 4 others). These people suffer from frictional unemployment, which refers to temporal transitions between jobs. These transactions may even be voluntary, i.e. people quitting their jobs in order to search for better jobs.
total frictional unemployment = 4 people
total labor force = 100 people
frictional unemployment rate = 4 / 100 = 4%