Seventeen percent of U. S. residents are in their thirties. Consider a group of nine U. S. residents selected at random. Find the probability that three or four of the people in the group are in their thirties.

0.1764

Step-by-step explanation:

This problem meets requirement that enables us to use the binomial probability relation :

Probability of success, p = 17% = 0.17

number of trials = 9

(1 - p) = 1 - 0.17 = 0.83

The binomial probability relation :

P(x = x) = nCx * p^x * (1 - p)^(n-x)

P(x = 3) = 9C3 * 0.17^3 * 0.83^6

P(x = 3) = 84 * 0.001606258054361897

P(x = 3) = 0.134925676566399348

P(x = 3) = 0.13492

P(x = 4) = 9C4 * 0.17^4 * 0.83^5

P(x = 4) = 126 * 0.000328992613544003

P(x = 4) = 0.041453069306544378

P(x = 4) = 0.04145

P(x = 3 or x = 4) = P(x = 3) + p(x = 4)

= 0.13492 + 0.04145

= 0.17637

= 0.1764

intensity of the vector is v= √37 ≈ 6.08 units and make angle ∡α ≈ 9.46° with east direction

step-by-step explanation:

required vector is consists of the two componentsvx= 2+4=6 units   and vy= 1 unit and vx ⊥ vywe will use pythagorian theorem to find intensity of the vector vv∧2 = vx∧2 + vy∧2 => v = √vx∧2 + vy∧2 = √6∧2 + 1∧2 = √36+1 = √37 ≈ 6.08 unitsthe angle ∡α between vector and east direction we wil find with tanαtanα = 1/6 => α = arc tanα = arc 1/6 => α ≈ 9.46°

hope this