... suất Y sau: T 1550 1850 20 25 P 0,03 0,090 20 75 0, 120 0,150 21 12, 5 21 25 0,110 0,50 E(T ) = 1550.0, 03+1850.0, 09 +20 25.0, 12+ 2075.0, 15 +21 12, 5.0, 11 +21 25.0, = 20 62, 125 (ngàn) Nếu thuê thêm ... 1+ x (x2 + a2 ) a Bài 2. 42 1 /20 f (x) = ; ; x (5; 25 ) x (5; 25 ) / P (|X 10| > 2, 5) = 1P (|X 10| 2, 5) = 1P (1 02, < X < 10 +2, 5) = 12, 5 1 =1 dx = ( 12, 7, 5) = 0, 75 20 7,5 20 25 25 + = 15 ... + 12. 0, + 13.0, 15 + 14.0, + 15.0, 05 = 11, 75 c) V (X) = 92 0, 05 + 1 02 0, 15 + 1 12 0, + 122 0, + 1 32 0, 15 + 1 42 0, + 1 52 0, 05 11, 7 52 = 2, 28 75 X = V (X) = 2, 28 75 = 1, 5 124 Bài 2. 24 X...