PENGANTAR METODE STATISTIKA KELAS CJURUSAN STATISTIKA2011Nama: Indi Yasinta Hadianti FiklianiNRP: 1311100114Assisten Dosen: Nuzilatul FirdausiStudi Kasus: Harga handphone dan fitur yang disediakan

I. DataData diambil pada tanggal 4 Desember 2011 dari majalah pulsa edisi 222 Th IX/2011/30 November-13 Desember. Dari majalah tersebut diambil data secara acak dengan kualifikasi merek handphone, banyaknya fitur yang disediakan dan harga yang dibandrol. Dari data yang telah diambil akan dihitung regresinya untuk mengetahui apakah handphone dengan harga tertentu mempengaruhi jumlah fitur yang ditawarkan.II. Analisa DataDari data yang sudah diambil secara acak akan dikualifikasikan kedalam kelompok jumlah fitur yang ditawarkan/predictor (x) dan harga/response (y), karena banyaknya fitur mempengaruhi harga handphone. Berikut tabel perhitungannya :Noxyx2y2xy

110250,00010062,500,000,0002,500,000

211300,00012190,000,000,0003,300,000

332800,0001,024640,000,000,00025,600,000

4351,000,0001,2251,000,000,000,00035,000,000

5332,999,0001,0898,994,001,000,00098,967,000

6312,450,0009616,002,500,000,00075,950,000

7353,100,0001,2259,610,000,000,000108,500,000

8363,075,0001,2969,455,625,000,000110,700,000

9343,775,0001,15614,250,625,000,000128,350,000

10404,175,0001,60017,430,625,000,000167,000,000

1124699,000576488,601,000,00016,776,000

1222500,000484250,000,000,00011,000,000

13231,000,0005291,000,000,000,00023,000,000

14271,000,0007291,000,000,000,00027,000,000

15222,599,0004846,754,801,000,00057,178,000

16242,449,0005765,997,601,000,00058,776,000

17213,100,0004419,610,000,000,00065,100,000

18463,500,0002,11612,250,000,000,000161,000,000

19464,400,0002,11619,360,000,000,000202,400,000

20303,850,00090014,822,500,000,000115,500,000

21221,400,0004841,960,000,000,00030,800,000

22263,499,00067612,243,001,000,00090,974,000

23323,200,0001,02410,240,000,000,000102,400,000

24373,000,0001,3699,000,000,000,000111,000,000

2532900,0001,024810,000,000,00028,800,000

26221,950,0004843,802,500,000,00042,900,000

27243,150,0005769,922,500,000,00075,600,000

28184,050,00032416,402,500,000,00072,900,000

2924900,000576810,000,000,00021,600,000

30211,600,0004412,560,000,000,00033,600,000

31243,650,00057613,322,500,000,00087,600,000

3216500,000256250,000,000,0008,000,000

3326475,000676225,625,000,00012,350,000

3420850,000400722,500,000,00017,000,000

3523745,000529555,025,000,00017,135,000

3620575,000400330,625,000,00011,500,000

37221,850,0004843,422,500,000,00040,700,000

38254,450,00062519,802,500,000,000111,250,000

39191,400,0003611,960,000,000,00026,600,000

40271,400,0007291,960,000,000,00037,800,000

41293,800,00084114,440,000,000,000110,200,000

4233500,0001,089250,000,000,00016,500,000

4314275,00019675,625,000,0003,850,000

4420250,00040062,500,000,0005,000,000

45341,225,0001,1561,500,625,000,00041,650,000

4624800,000576640,000,000,00019,200,000

4728400,000784160,000,000,00011,200,000

4821599,000441358,801,000,00012,579,000

49201,200,0004001,440,000,000,00024,000,000

50292,100,0008414,410,000,000,00060,900,000

Total1,31495,714,00037,486272,708,706,000,0002,779,185,000

Dari tabel diatas dapat dihitung beberapa aspek dari analisis regresi, seperti : = = = 26,28 = = = 1.914.280 = = 37.486 - 50(26,28)2 = 2.954,08 = = 272.708.706.000 - 50(1.914.280)2 = 8,94853E+13 = = 2.779.185.000-50(26,28)2(1.914.280)2 = 2,6E+08 = = = 89.307,35796 = - = 1.914.280 ( 89.307,35796 x 26,28 ) = -432.717 = - = 8,94853E+13 = 6,6E+13 = + = -432.717 + 89.307.35796Perhitungan minitab sebagai berikut :

12/5/2011 11:29:03 PM Welcome to Minitab, press F1 for help. Regression Analysis: y versus x The regression equation isy = - 432717 + 89307 xPredictor Coef SE Coef T PConstant -432717 590391 -0.73 0.467x 89307 21562 4.14 0.000S = 1171930 R-Sq = 26.3% R-Sq(adj) = 24.8%Analysis of VarianceSource DF SS MS F PRegression 1 2.35612E+13 2.35612E+13 17.16 0.000Residual Error 48 6.59241E+13 1.37342E+12Total 49 8.94853E+13Unusual ObservationsObs x y Fit SE Fit Residual St Resid 18 46.0 3500000 3675421 456363 -175421 -0.16 X 19 46.0 4400000 3675421 456363 724579 0.67 X 28 18.0 4050000 1174815 243604 2875185 2.51R 38 25.0 4450000 1799967 168018 2650033 2.28RR denotes an observation with a large standardized residual.X denotes an observation whose X value gives it large leverage.

Dengan pengujian hipoteisis :H0 : = 0 (jumlah fitur tidak mempengaruhi harga handphone)H1 : 0 (jumlah fitur mempengaruhi harga handpphone)Dengan uji thitung dan tingkat kepercayaan 95%, maka : = = = = 4,7334E-05 x 89.307 = 4,22ttabel dengan df : 48 = 1,684 (df : 40 mendekati 48)Karena nilai thitung > ttabel maka kita dapat menolak H0.

III. Penarikan KesimpulanKesimpulan yang dapat diambil dari hasil analisa diatas bahwa banyaknya fitur yang disediakan pada tipe handphone tertentu mempengaruhi harga yang diminta produsen. Semakin banyak fitur yang disediakan dan semakin berkualitas fitur yang disediakan maka semakin mahal harga handphone tersebut. Berikut tampilan gambar scatterplot dengan menggunakan minitab :