The following data represent the monthly phone use, in minutes, of a customer enrolled in a fraud prevention program for the past 20 months. The phone company decides to use the upper fence as the cutoff point for the number of minutes at which the customer should be contacted. What is the cutoff point?

321 474 461 548

406 464 517 311

534 425 377 505

322 435 410 513

499 354 307 363

The cutoff point is minutes( round to the nearest minute)