Quiz 4 Mark: 1'12 Last Name: First Name: Set: |+P B)P[AAB) P[A}XP:B|A\\ PlAABl ' dependent) l. A recent study of online users under age 25 found that 78% use Snapchat 45% use Twitter and 40% use both. For online users under age 25 answer the following: (a) What percentage do not use Twitter? [2 marks] ANSWER: (b) What percentage use at least one of these two social networks? [2 marks] ANSWER: (c) What percentage use none of these social networks? [2 marks] ANSWER: (d) What percentage use Twitter but do not use Snapchat (Le. they use only Twitter?) Hint: Draw a Venn Diagram or set up a 2 X 2 probability table. [2 marks] ANSWER: (e) Iftwo events are independent then PEA mid Bi:PlAlXPlBi Cheek to see if the two events, Uses Snapshot and Uses Twitter are independent. [3] ANSWER: Quiz 4 Mark: 1'12 (1) If someone uses Snapehat does that change the probability they use Twitter? [1 mark] Circle the correct answer: YES NO