12-12:4=9(см)
ответ: длина прямоугольника равна 9 см
X. p(x)
0. 0.7^4. 0.2401
1. 4*0.7^3*0.3 0.41116
2. 6*0.7^2*0.3^2. 0.2646
3. 4*0.7*0.3^3. 0.0756
4. 0.3^4. 0.0081
М(х)= 0*0.2401+1*0.4116+2*0.2646+3*0.0756+4*0.0081=1.2
D(x)= 0.2401*1,2^2+0.4116*0.2^2+0.2646*0.8^2+0.0756*1,8^2+0.0081*2.8^2= 0.84
q(x)= √D(x) = ~0.92
2096000 клограмов в 1 тонне 1000 кг
и 20960 центнероа в 1 тонне 10 центнеров
<span><em>27+54=81</em></span>
<span><em>63+25=88</em></span>
:)))
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