PhscsAndMathsTutor.com
phscsandmathstutor.com June 005 5. The random varable X has probablt functon k, = 1,, 3, P( X = ) = k ( + 1), = 4, 5, where k s a constant. (a) Fnd the value of k. (b) Fnd the eact value of E(X). (c) Show that, to 3 sgnfcant fgures, Var(X) = 1.47. (d) Fnd, to 1 decmal place, Var(4 3X). (4) 1 *N0910A010*
phscsandmathstutor.com June 005 Queston 5 contnued *N0910A0130* 13 Turn over
phscsandmathstutor.com June 006 4. The random varable X has the dscrete unform dstrbuton P(X = ) = 1, = 1,, 3, 4, 5. 5 (a) Wrte down the value of E(X) and show that Var(X) =. (3) Fnd (b) E(3X ), (c) Var(4 3X). 1 *N337A010*
phscsandmathstutor.com Januar 007 3. The random varable X has probablt functon ( 1) P(X = ) = = 1,, 3, 4, 5, 6. 36 (a) Construct a table gvng the probablt dstrbuton of X. (3) Fnd (b) P( < X 5), (c) the eact value of E(X). (d) Show that Var(X) = 1.97 to 3 sgnfcant fgures. (e) Fnd Var( 3X). (4) 8 *N3957A080*
phscsandmathstutor.com Januar 007 Queston 3 contnued Q3 (Total 13 marks) *N3957A090* 9 Turn over
phscsandmathstutor.com June 007 7. The random varable X has probablt dstrbuton 1 3 5 7 9 P(X = ) 0. p 0. q 0.15 (a) Gven that E(X) = 4.5, wrte down two equatons nvolvng p and q. (3) Fnd (b) the value of p and the value of q, (c) P(4 < X 7). (3) Gven that E(X ) = 7.4, fnd (d) Var(X ), (e) E(19 4X), (1) (f) Var(19 4X). 0 *N6118A004*
phscsandmathstutor.com June 007 Queston 7 contnued (Total 13 marks) TOTAL FOR PAPER: 75 MARKS Q7 END *N6118A034* 3
phscsandmathstutor.com June 008 3. The random varable X has probablt dstrbuton gven n the table below. 1 0 1 3 P(X = ) p q 0. 0.15 0.15 Gven that E(X) = 0.55, fnd (a) the value of p and the value of q, (b) Var(X), (5) (4) (c) E( X 4). 10 *H358A0108*
phscsandmathstutor.com June 008 Queston 3 contnued *H358A0118* 11 Turn over
phscsandmathstutor.com Januar 009 3. When Roht plas a game, the number of ponts he receves s gven b the dscrete random varable X wth the followng probablt dstrbuton. 0 1 3 P(X = ) 0.4 0.3 0. 0.1 (a) Fnd E(X). (b) Fnd F(1.5). (c) Show that Var(X) = 1 (d) Fnd Var(5 3X). (4) Roht can wn a prze f the total number of ponts he has scored after 5 games s at least 10. After 3 games he has a total of 6 ponts. You ma assume that games are ndependent. (e) Fnd the probablt that Roht wns the prze. (6) 10 *N3680A0104*
phscsandmathstutor.com Januar 009 Queston 3 contnued *N3680A0114* 11 Turn over
phscsandmathstutor.com June 009 6. The dscrete random varable X has probablt functon P( X = ) = a (3 ) = 0,1, b = 3 (a) Fnd P(X = ) and complete the table below. 0 1 3 P(X = ) 3a a b (1) Gven that E(X) = 1.6 (b) Fnd the value of a and the value of b. (5) Fnd (c) P(0.5 < X < 3), (d) E(3X ). (e) Show that the Var(X) = 1.64 (3) (f) Calculate Var(3X ). 16 *H3479A0164*
phscsandmathstutor.com June 009 Queston 6 contnued *H3479A0174* 17 Turn over
phscsandmathstutor.com Januar 010 5. The probablt functon of a dscrete random varable X s gven b p( ) = k = 1,, 3 where k s a postve constant. (a) Show that 1 k = 14 Fnd (b) P(X ) (c) E(X) (d) Var(1 X) (4) 14 *N35711A0144*
phscsandmathstutor.com Januar 010 Queston 5 contnued Q5 (Total 10 marks) *N35711A0154* 15 Turn over
phscsandmathstutor.com June 010 3. The dscrete random varable X has probablt dstrbuton gven b 1 0 1 3 P( X = ) 1 5 a 1 10 a 1 5 where a s a constant. (a) Fnd the value of a. (b) Wrte down E( X ). (c) Fnd Var( X ). (1) (3) The random varable Y = 6 X (d) Fnd Var( Y ). (e) Calculate P( X Y). (3) 8 *H35395A088*
phscsandmathstutor.com June 010 Queston 3 contnued *H35395A098* 9 Turn over
phscsandmathstutor.com Januar 011 6. The dscrete random varable X has the probablt dstrbuton 1 3 4 P(X = ) k k 3k 4k (a) Show that k = 0.1 (1) Fnd (b) E(X ) (c) E(X ) (d) Var( 5 X ) (3) Two ndependent observatons X 1 and X are made of X. (e) Show that P(X 1 + X = 4) = 0.1 (f) Complete the probablt dstrbuton table for X 1 + X 3 4 5 6 7 8 P(X 1 + X = ) 0.01 0.04 0.10 0.5 0.4 (g) Fnd P(1.5 X 1 + X 3.5) 1 *H35410A014*
phscsandmathstutor.com Januar 011 Queston 6 contnued *H35410A0134* 13 Turn over
phscsandmathstutor.com June 011. The random varable X ~ N ( µ, 5 ) and P( X 3) = 0.919 (a) Fnd the value of (µ. (4) (b) Wrte down the value of P( µ < X < 3). (1) 4 *P38164A044*
phscsandmathstutor.com June 011 3. The dscrete random varable Y has probablt dstrbuton 1 3 4 P(Y = ) a b 0.3 c where a, b and c are constants. The cumulatve dstrbuton functon F() of Y s gven n the followng table 1 3 4 F() 0.1 0.5 d 1.0 where d s a constant. (a) Fnd the value of a, the value of b, the value of c and the value of d. (5) (b) Fnd P(3Y + 8). 6 *P38164A064*
phscsandmathstutor.com Januar 01 3. The dscrete random varable X can take onl the values, 3, 4 or 6. For these values the probablt dstrbuton functon s gven b 3 4 6 P(X = ) 5 1 where k s a postve nteger. k 1 7 1 k 1 (a) Show that k = 3 Fnd (b) F(3) (c) E(X) (d) E ( X ) (1) (e) Var(7 5) (4) 6 *P40699A064*
phscsandmathstutor.com Januar 01 Queston 3 contnued *P40699A074* 7 Turn over
phscsandmathstutor.com June 01 1. A dscrete random varable X has the probablt functon P ( X = ) = { k( 1 ) = 1, 0, 1 and 0 otherwse (a) Show that k = 1 6 (b) Fnd E(X) 4 (c) Show that E( X ) = 3 (3) (d) Fnd Var(1 3X) (3) *P40105XA04*
phscsandmathstutor.com Januar 013. The dscrete random varable X can take onl the values 1, and 3. For these values the cumulatve dstrbuton functon s defned b 3 + k F( ) = = 13,, 40 (a) Show that k = 13 (b) Fnd the probablt dstrbuton of X. Gven that Var(X) = 59 30 (4) (c) fnd the eact value of Var(4X 5). 4 *P41805A040*
phscsandmathstutor.com Januar 013 6. A far blue de has faces numbered 1, 1, 3, 3, 5 and 5. The random varable B represents the score when the blue de s rolled. (a) Wrte down the probablt dstrbuton for B. (b) State the name of ths probablt dstrbuton. (c) Wrte down the value of E(B). (1) (1) A second de s red and the random varable R represents the score when the red de s rolled. The probablt dstrbuton of R s r 4 6 P(R = r) 3 1 6 1 6 (d) Fnd E(R). (e) Fnd Var(R). (3) Tom nvtes Avsha to pla a game wth these dce. Tom spns a far con wth one sde labelled and the other sde labelled 5. When Avsha sees the number showng on the con she then chooses one of the dce and rolls t. If the number showng on the de s greater than the number showng on the con, Avsha wns, otherwse Tom wns. Avsha chooses the de whch gves her the best chance of wnnng each tme Tom spns the con. (f) Fnd the probablt that Avsha wns the game, statng clearl whch de she should use n each case. (4) 14 *P41805A0140*
phscsandmathstutor.com Januar 013 Queston 6 contnued *P41805A0150* 15 Turn over
phscsandmathstutor.com June 013 (R). The dscrete random varable X takes the values 1, and 3 and has cumulatve dstrbuton functon F() gven b 1 3 F() 0.4 0.65 1 (a) Fnd the probablt dstrbuton of X. (3) (b) Wrte down the value of F(1.8). (1) Q (Total 4 marks) *P43956A054* 5 Turn over
phscsandmathstutor.com June 013 (R) 7. The score S when a spnner s spun has the followng probablt dstrbuton. s 0 1 4 5 P(S = s) 0. 0. 0.1 0.3 0. (a) Fnd E(S). (b) Show that E(S ) = 10.4 (c) Hence fnd Var(S). (d) Fnd () E(5S 3), () Var(5S 3). (e) Fnd P(5S 3 > S + 3) (4) (3) The spnner s spun twce. The score from the frst spn s S 1 and the score from the second spn s S The random varables S 1 and S are ndependent and the random varable X = S 1 S (f) Show that P({S 1 = 1} X < 5) = 0.16 (g) Fnd P(X < 5). (3) *P43956A04*
phscsandmathstutor.com June 013 (R) Queston 7 contnued Q7 (Total 18 marks) END TOTAL FOR PAPER: 75 MARKS 4 *P43956A044*
phscsandmathstutor.com June 013 5. A based de wth s faces s rolled. The dscrete random varable X represents the score on the uppermost face. The probablt dstrbuton of X s shown n the table below. 1 3 4 5 6 P(X = ) a a a b b 0.3 (a) Gven that E(X) = 4. fnd the value of a and the value of b. (b) Show that E(X ) = 0.4 (c) Fnd Var(5 3X) (5) (1) (3) A based de wth fve faces s rolled. The dscrete random varable Y represents the score whch s uppermost. The cumulatve dstrbuton functon of Y s shown n the table below. 1 3 4 5 F() 1 10 10 3k 4k 5k (d) Fnd the value of k. (e) Fnd the probablt dstrbuton of Y. (1) (3) Each de s rolled once. The scores on the two dce are ndependent. (f) Fnd the probablt that the sum of the two scores equals 18 *P4831A0184*
phscsandmathstutor.com June 013 Queston 5 contnued *P4831A0194* 19 Turn over
Statstcs S1 Probablt P( A B ) = P( A ) + P( B ) P( A B ) P( A B ) = P( A ) P( B A ) P( B A ) P( A ) P( A B ) = P( B A ) P( A ) + P( B A ) P( A ) Dscrete dstrbutons For a dscrete random varable X takng values wth probabltes P(X = ) Epectaton (mean): E(X) = µ = P(X = ) Varance: Var(X) = σ = ( µ ) P(X = ) = P(X = ) µ For a functon g(x ) : E(g(X)) = g( ) P(X = ) Contnuous dstrbutons Standard contnuous dstrbuton: Dstrbuton of X P.D.F. Mean Varance Normal N( µ, σ ) 1 µ 1 σ e σ π µ σ 16 Edecel AS/A level Mathematcs Formulae Lst: Statstcs S1 Issue 1 September 009
Edecel AS/A level Mathematcs Formulae Lst: Statstcs S1 Issue 1 September 009 17 Correlaton and regresson For a set of n pars of values ), ( n S ) ( ) ( = = n S ) ( ) ( = = n S ) )( ( ) )( ( = = The product moment correlaton coeffcent s = = = n n n S S S r ) ( ) ( ) )( ( ) ( ) ( ) )( ( } }{ { The regresson coeffcent of on s ) ( ) )( ( S S b = = Least squares regresson lne of on s b a + = where b a =
THE NORMAL DISTRIBUTION FUNCTION The functon tabulated below s Φ(z), defned as Φ(z) = z 1 1 t π e dt. z Φ(z) z Φ(z) z Φ(z) z Φ(z) z Φ(z) 0.00 0.5000 0.50 0.6915 1.00 0.8413 1.50 0.933.00 0.977 0.01 0.5040 0.51 0.6950 1.01 0.8438 1.51 0.9345.0 0.9783 0.0 0.5080 0.5 0.6985 1.0 0.8461 1.5 0.9357.04 0.9793 0.03 0.510 0.53 0.7019 1.03 0.8485 1.53 0.9370.06 0.9803 0.04 0.5160 0.54 0.7054 1.04 0.8508 1.54 0.938.08 0.981 0.05 0.5199 0.55 0.7088 1.05 0.8531 1.55 0.9394.10 0.981 0.06 0.539 0.56 0.713 1.06 0.8554 1.56 0.9406.1 0.9830 0.07 0.579 0.57 0.7157 1.07 0.8577 1.57 0.9418.14 0.9838 0.08 0.5319 0.58 0.7190 1.08 0.8599 1.58 0.949.16 0.9846 0.09 0.5359 0.59 0.74 1.09 0.861 1.59 0.9441.18 0.9854 0.10 0.5398 0.60 0.757 1.10 0.8643 1.60 0.945.0 0.9861 0.11 0.5438 0.61 0.791 1.11 0.8665 1.61 0.9463. 0.9868 0.1 0.5478 0.6 0.734 1.1 0.8686 1.6 0.9474.4 0.9875 0.13 0.5517 0.63 0.7357 1.13 0.8708 1.63 0.9484.6 0.9881 0.14 0.5557 0.64 0.7389 1.14 0.879 1.64 0.9495.8 0.9887 0.15 0.5596 0.65 0.74 1.15 0.8749 1.65 0.9505.30 0.9893 0.16 0.5636 0.66 0.7454 1.16 0.8770 1.66 0.9515.3 0.9898 0.17 0.5675 0.67 0.7486 1.17 0.8790 1.67 0.955.34 0.9904 0.18 0.5714 0.68 0.7517 1.18 0.8810 1.68 0.9535.36 0.9909 0.19 0.5753 0.69 0.7549 1.19 0.8830 1.69 0.9545.38 0.9913 0.0 0.5793 0.70 0.7580 1.0 0.8849 1.70 0.9554.40 0.9918 0.1 0.583 0.71 0.7611 1.1 0.8869 1.71 0.9564.4 0.99 0. 0.5871 0.7 0.764 1. 0.8888 1.7 0.9573.44 0.997 0.3 0.5910 0.73 0.7673 1.3 0.8907 1.73 0.958.46 0.9931 0.4 0.5948 0.74 0.7704 1.4 0.895 1.74 0.9591.48 0.9934 0.5 0.5987 0.75 0.7734 1.5 0.8944 1.75 0.9599.50 0.9938 0.6 0.606 0.76 0.7764 1.6 0.896 1.76 0.9608.55 0.9946 0.7 0.6064 0.77 0.7794 1.7 0.8980 1.77 0.9616.60 0.9953 0.8 0.6103 0.78 0.783 1.8 0.8997 1.78 0.965.65 0.9960 0.9 0.6141 0.79 0.785 1.9 0.9015 1.79 0.9633.70 0.9965 0.30 0.6179 0.80 0.7881 1.30 0.903 1.80 0.9641.75 0.9970 0.31 0.617 0.81 0.7910 1.31 0.9049 1.81 0.9649.80 0.9974 0.3 0.655 0.8 0.7939 1.3 0.9066 1.8 0.9656.85 0.9978 0.33 0.693 0.83 0.7967 1.33 0.908 1.83 0.9664.90 0.9981 0.34 0.6331 0.84 0.7995 1.34 0.9099 1.84 0.9671.95 0.9984 0.35 0.6368 0.85 0.803 1.35 0.9115 1.85 0.9678 3.00 0.9987 0.36 0.6406 0.86 0.8051 1.36 0.9131 1.86 0.9686 3.05 0.9989 0.37 0.6443 0.87 0.8078 1.37 0.9147 1.87 0.9693 3.10 0.9990 0.38 0.6480 0.88 0.8106 1.38 0.916 1.88 0.9699 3.15 0.999 0.39 0.6517 0.89 0.8133 1.39 0.9177 1.89 0.9706 3.0 0.9993 0.40 0.6554 0.90 0.8159 1.40 0.919 1.90 0.9713 3.5 0.9994 0.41 0.6591 0.91 0.8186 1.41 0.907 1.91 0.9719 3.30 0.9995 0.4 0.668 0.9 0.81 1.4 0.9 1.9 0.976 3.35 0.9996 0.43 0.6664 0.93 0.838 1.43 0.936 1.93 0.973 3.40 0.9997 0.44 0.6700 0.94 0.864 1.44 0.951 1.94 0.9738 3.50 0.9998 0.45 0.6736 0.95 0.889 1.45 0.965 1.95 0.9744 3.60 0.9998 0.46 0.677 0.96 0.8315 1.46 0.979 1.96 0.9750 3.70 0.9999 0.47 0.6808 0.97 0.8340 1.47 0.99 1.97 0.9756 3.80 0.9999 0.48 0.6844 0.98 0.8365 1.48 0.9306 1.98 0.9761 3.90 1.0000 0.49 0.6879 0.99 0.8389 1.49 0.9319 1.99 0.9767 4.00 1.0000 0.50 0.6915 1.00 0.8413 1.50 0.933.00 0.977 18 Edecel AS/A level Mathematcs Formulae Lst: Statstcs S1 Issue 1 September 009
PERCENTAGE POINTS OF THE NORMAL DISTRIBUTION The values z n the table are those whch a random varable Z N(0, 1) eceeds wth probablt p; that s, P(Z > z) = 1 Φ(z) = p. p z p z 0.5000 0.0000 0.0500 1.6449 0.4000 0.533 0.050 1.9600 0.3000 0.544 0.0100.363 0.000 0.8416 0.0050.5758 0.1500 1.0364 0.0010 3.090 0.1000 1.816 0.0005 3.905 Edecel AS/A level Mathematcs Formulae Lst: Statstcs S1 Issue 1 September 009 19