17 1 point possible (graded) What is the term used to indicate the difference between the first and third quartiles? lower whisker and upper whisker. first quartile third quartile Interquartile Range unanswered SaveSave your answer Submit You have used 0 of 2 attemptsSome problems have options such as save, reset, hints, or show answer. These options follow the Submit button. Question 18 1 point possible (graded) Which function gives an object that represents an empty world map addMarkers addTiles leaflet All the options above are correct unanswered SaveSave your answer Submit You have used 0 of 2 attemptsSome problems have options such as save, reset, hints, or show answer. These options follow the Submit button. Question 19 1 point possible (graded) What is the use of the method addTiles() in R? To divide map in tiles. To zoom in the map to see different countries and streets in detail. To create tiles view of map. All the options above are correct unanswered SaveSave your answer Submit You have used 0 of 2 attemptsSome problems have options such as save, reset, hints, or show answer. These options follow the Submit button. Question 20 1 point possible (graded) Which function is used to create display of shiny app ? display() output functions fluidPage() input functions