Відповідь:

1,89

Покрокове пояснення:

p=0.3

q=1-p=0.7

X={0, 1, 2, 3, 4, 5, 6, 7, 8, 9}

p(0)=C(0,9)p⁰q⁹=1×0.3⁰×0.7⁹=0,040353607

p(1)=C(1,9)pq⁸=9×0.3×0.7⁸=0,155649627

p(2)=0,266827932

p(3)=0,266827932

p(4)=0,171532242

p(5)=0,073513818

p(6)=0,021003948

p(7)=0,003857868

p(8)=0,000413343

p(9)=0,000019683

Mx=0×0,040353607+1×0,155649627+2×0,266827932+3×0,266827932+4×0,171532242+

5×0,073513818+6×0,021003948+7×0,003857868+8×0,000413343+9×0,000019683=2,7

Mx²=0×0,040353607+1×0,155649627+4×0,266827932+9×0,266827932+16×0,171532242+25×0,073513818+36×0,021003948+49×0,003857868+64×0,000413343+81×0,000019683=9,18

Dx=Mx²-(Mx)²=9,18-2,7²=1,89