A cellular phone company monitors monthly phone usage. The following data represent the monthly phone use in minutes of one particular customer for the past 20 months. Use the given data to answer parts​ (a) and​ (b). 336 405 334 471 503 378378 560560 436 551 536 458 404 380 498 356 473 477 505 502 484 Question content area bottom Part 1 ​(a) Determine the standard deviation and interquartile range of the data. sequals=enter your response here ​(Round to two decimal places as​ needed.)