6 Aish h sab g co ainig 3 red b lls ad 3 wh te b lls. Sb selects a b ll at rach , b es its cb o ad return it to th b g th same p o ess is rep ated twice mo e. Tb m brd red b lls selected b Aish is d no edy \(X\).

1. Fid \(\mathbf { b } \mathbf { p b }\) b lityg \(\mathbf { a }\) ratig \(\mathbf { a }\) ting \({ } _ { X } ( t ) \boldsymbol { 6 } X\). Basan also s sab g co ain g 3 red balls ad 3 wh te b lls. He selects th ee b lls at rach , with rep acemen, frm hsbg Th m brg red lls selectedB asan is d n edy \(Y\).
2. Fid \(\mathbf { b } \mathbf { p } \mathbf { b }\) b litys \(\mathbf { a }\) ratif \(\mathbf { a }\) ting \({ } _ { Y } ( t ) \underset { \text { b } } { } Y\). Th rad \(m\) riab e \(Z\) is to to alm brø reb lls selected y Aish adB asan.
3. Fid \(\mathbf { b } \mathbf { p } \mathbf { b }\) b lityg \(\mathbf { e }\) ratig \(\mathbf { u }\) tim \(Z\), essig as wer as \(\mathrm { p } \mathbf { p }\) ial. [β
4. Use th p b b lityg \(\mathbf { B }\) ratig u tim \(Z\) tof idE ( \(Z\) ) ad \(\operatorname { Var } ( Z )\). [\$ If B e th follw ig lin dpg to cm p ete th an wer(s) to ay q stin (s), th q stin \(\mathrm { m } \quad \mathbf { b } \quad \mathrm { r } ( \mathrm { s } )\) ms tb clearlys n n