An experiment consists of repeatedly and independently tossing a fair die until number four is obtained. Let X denote the number of throws until we get three fours. Then E(X) is Select one: O a. 1/5 O...

Extracted text: An experiment consists of repeatedly and independently tossing a fair die until number four is obtained. Let X denote the number of throws until we get three fours. Then E(X) is Select one: O a. 1/5 O b. 15 O c. 6/5 O d. 18 FINISH ATTEMPT...