Assume that a lost treasure will be in a certain area of the ocean with probability 0.4, and that a search of that area will find the treasure with probability 0.9 if it is there. What is the conditional probability of the treasure being in the area if the area is searched and no treasure is found?

the probability of the treasure being in the area given that no treasure is found is 0.0625 (6.25%)

Step-by-step explanation:

denoting the event N= no treasure is found , then

P(N) = probability that the lost treasure is in the area* probability that the lost treasure is not found in the treasure's area + probability that the lost treasure is not in the area*  probability that the lost treasure is not found in other areas = 0.4*0.1 + 0.6*1 = 0.64

P(N) = 0.64

then we can get the conditional probability using the theorem of Bayes . Denoting the event A= the treasure being in the area

P(A/N) = P(A∩N)/P(N) = 0.4*0.1/0.64 = 0.0625 (6.25%)

where

P(A∩N) = probability of the treasure being in the area and no treasure is found

P(A/N) = probability of the treasure being in the area given that no treasure is found

3. parallelogram

step-by-step explanation:

we turn each of our sides into direction vectors

ab=b-a=(3 - 7, 1 - 0) = (-4, 1)

bc=c-b=(1,6)

cd=d-c=(4,-1)

da=a-d=(-1,-6)

we see how the opposite sides have negated direction vectors; this is characteristic of a parallelogram.   we have congruent sides ab=cd and bc=da with unequal lengths because 1^2+6^2 is different from (-4)^2+1^2.   so it's not a square or a rhombus.  

we check the dot product of direction vectors of adjacent sides.   we have

ab dot bc = -4(1) + 1(6) = 2

that's not zero so the sides are not perpendicular.   we've ruled out rectangle.

the direction vectors indicate two pairs of congruent parallel sides, so we choose parallelogram over trapezoid.

47

step-by-step explanation: