Not all telephone polls carried out to estimate

voter or consumer preferences make calls to cell

phones. one reason is that in the usa, automated

calls ("robocalls") to cell phones are not

permitted and interviews conducted by humans

are more costly.

a. how might the strategy of leaving out cell

phones affect the goal of obtaining a random

sample of voters or consumers?

b. which criterion of random sampling is most

likely to be violated by the problems you

identifi ed in part (a): equal chance of being

selected, or the independence of the selection

of individuals?

c. which attribute of estimated consumer preference

is most affected by the problem you

identifi ed in (a): accuracy or precision?

a) See answer below.

b) Equal chance of being selected.

c) Accuracy

Step-by-step explanation:

a. How might the strategy of leaving out cell phones affect the goal of obtaining a random sample of voters of consumers?

This strategy might affect the goal of obtaining a random sample by not choosing the sample from all the population of the USA. People who don't have a landline an only have a cell phone will have zero chance of being selected and therefore the polls will not be accurate.

b. Which criterion of random sampling is most likely to be violated by the problems you identified in part (a)?

Equal chance of being selected, since the people who only have cell phones will not be selected for the poll, this criterion of random sampling will be violated.

c. Which attribute of estimated consumer preference is most affected by the problem you identified in (a)

Accuracy. The definition of accuracy is how close a value really is to its true value.

By not selecting the sample from all the population, the results of the poll will likely be biased and therefore they might not be close to the actual preferences of consumers or voters.

geometry: triangles

solvers

lessons

answers archive

call the larger triangle abc

then the smaller triangle cde is similar to abc (all angles are equal, aaa).  

ab is the side that is 36, and we wish to find de, the side corresponding to ab

area_cde = area_abc - area_cde --> area_abc / area_cde = 2

let x=length of de

ratio of areas = (ratio of sides)^2

+2+=+%2836%2fx%29%5e2+

+2+=+1296%2fx%5e2+

++x%5e2+=+1296%2f2+=+648+

25.45584

{x = -1/2 ,   y = -1

step-by-step explanation:

solve the following system:

{2 x + y = -2

{10 x - 3 y = -2

in the first equation, look to solve for y:

{2 x + y = -2

{10 x - 3 y = -2

subtract 2 x from both sides:

{y = -2 x - 2

{10 x - 3 y = -2

substitute y = -2 x - 2 into the second equation:

{y = -2 x - 2

{10 x - 3 (-2 x - 2) = -2

10 x - 3 (-2 x - 2) = (6 x + 6) + 10 x = 16 x + 6:

{y = -2 x - 2

{16 x + 6 = -2

in the second equation, look to solve for x:

{y = -2 x - 2

{16 x + 6 = -2

subtract 6 from both sides:

{y = -2 x - 2

{16 x = -8

divide both sides by 16:

{y = -2 x - 2

{x = -1/2

substitute x = -1/2 into the first equation:

{y = -1

{x = -1/2

collect results in alphabetical order:

answer:   {x = -1/2 ,   y = -1