What is the interquartile range of the data set? {18, 17, 10, 25, 20, 20, 30, 18, 18, 30, 25} enter the answer in the box. hurry up

Plz me plz i will give a brain just plz

What are the possible rational zeros of [tex]f(x) = x^4+2x^3-3x^2-4x+18[/tex]

One of every 20 customers reports poor customer service on your company’s customer satisfaction survey. you have just created a new process that should cut the number of poor customer service complaints in half. what percentage of customers would you expect to report poor service after this process is implemented? 1.) 5% 2.) 10% 3.) 2% 4.) 2.5%