Question

Samples from two brands of a machine part in a manufacturing process are collected, and their diameters (in inches) are measured, giving the following results: Sampel dari dua jenama bahagian mesin dalam proses pembuatan dikumpulkan, dan diameternya (dalam inci) diukur, memberikan hasil berikut: Brand A Brand B (Jenama Aj Jenama B] 10 16 Sample size (Saiz sampell Standard deviation (Sisihan piawai] 0.0428 0.0395 Calculate a 90% interval estimate for the ratio of the two populations variances, [Hitung anggaran 90% selang keyakinan untuk nisbah dua variasi populasi, A. (0.4184, 32615) B. (1.0449, 2.8276) C. (0.3012, 5.8234) D. (0.4533, 3.5339)

Answer 1

a= 0.1 Given 90% confidence Level of significance Numerator degrees of freedom Denominator degrees of freedom n-1= n-1= 9 15 Critical value F II 2.5876 From Ftable Critical value 0.3327 From Ftable Sample variance F 2 52 = sz? = 0.001832 Sample variance = 0.00156 5? 15 - Lower bound 0.4533 F 1 Upper bound 51/5, 11 3.5339 F Sie Answer:D