A new cola company is testing to see what proportion of their cans contain at least 12 oz. If they want to be within 3% of the actual percentage, how many cans should they measure to be 90% confident

752

Step-by-step explanation:

Given that,

Margin of error = 3% = 0.03

confidence level = 90% = 0.90

therefore from the z-table

z = 1.645

Now since no prior estimate of p is given, so we say p = 0.5

Sample size required will be

n = 1.645² × 0.5 ×(1-0.5) / 0.03² = 751.67

n = 751.67 ≈ 752

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.

answer: 12

step-by-step explanation: