poultry prices at each of three statewide CR

[poonam1279]

For several consecutive years, poultry prices at each of three statewide grocery-store chains have exceeded the national average by about fifty percent. Also, the per-pound difference in poultry prices among the three stores never amounted to more than a few pennies, while among grocery stores in other states, the prices varied by nearly a dollar over the same period. The three chains must have conspired to not compete amongst themselves and to fix their poultry prices at mutually agreed-upon levels.

The claim that the three grocery-store chains conspired to fix poultry prices rests on which of the following assumptions for the time period referred to above?

(A) No other grocery store charged higher prices for poultry than the three chains.
(B) Average poultry prices in the state where the three chains operate exceeded the national average.
(C) The price that grocery stores paid for poultry did not vary significantly from state to state.
(D) Consumers in the state where the three chains operate generally prefer poultry over other meats even if poultry is more expensive than other meats.
(E) Other grocery stores operating in the same state as the three chains also sell poultry to consumers.

[parallel_chase]

IMO C

the per-pound difference in poultry prices among the three stores never amounted to more than a few pennies

if the three stores charge approximately the same price, they would also buy approximately at the same price.

Hence C

OA?

[iamcste]

For several consecutive years, poultry prices at each of three statewide grocery-store chains have exceeded the national average by about fifty percent. Also, the per-pound difference in poultry prices among the three stores never amounted to more than a few pennies, while among grocery stores in other states, the prices varied by nearly a dollar over the same period. The three chains must have conspired to not compete amongst themselves and to fix their poultry prices at mutually agreed-upon levels.

The claim that the three grocery-store chains conspired to fix poultry prices rests on which of the following assumptions for the time period referred to above?

(A) No other grocery store charged higher prices for poultry than the three chains.
(B) Average poultry prices in the state where the three chains operate exceeded the national average.
(C) The price that grocery stores paid for poultry did not vary significantly from state to state.
(D) Consumers in the state where the three chains operate generally prefer poultry over other meats even if poultry is more expensive than other meats.
(E) Other grocery stores operating in the same state as the three chains also sell poultry to consumers.

C is right

[Spring2009]

Agree with C.

[logitech]

For several consecutive years, poultry prices at each of three statewide grocery-store chains have exceeded the national average by about fifty percent. Also, the per-pound difference in poultry prices among the three stores never amounted to more than a few pennies, while among grocery stores in other states, the prices varied by nearly a dollar over the same period. The three chains must have conspired to not compete amongst themselves and to fix their poultry prices at mutually agreed-upon levels.

The claim that the three grocery-store chains conspired to fix poultry prices rests on which of the following assumptions for the time period referred to above?

It is always easy to negate a negative sentence:

(C) The price that grocery stores paid for poultry did not vary significantly from state to state.

The price that grocery stores paid for poultry did vary significantly from state to state.

Conc: The three chains must have conspired to not compete amongst themselves and to fix their poultry prices at mutually agreed-upon levels.

The conclusion is not valid if we negate C .

Choose (C)

[poonam1279]

Thanks to all of you for explanations. C is correct answer
Analysis

The correct answer is (C). The argument relies on the assumption that all other possible factors in the price grocery stores charge for poultry were essentially the same in the state where the three chains operate as in other states. One such factor is wholesale price (the price grocery stores pay suppliers for poultry). A higher wholesale price generally leads to higher prices for consumers. Answer choice (C) expressly eliminates this factor. Admittedly, an "ideal" answer choice would provide a more sweeping statement—that all factors possibly affecting poultry price were the same from state to state. Nevertheless, (C) is the only answer choice that serves to affirm the assumption; thus (C) is the best choice.

(A) admittedly provides some support for the argument. Higher poultry prices at another store would weaken the argument that the three chains conspired to fix prices; thus given the inverse -- that no other store charges higher poultry prices—the argument's conclusion becomes more probable. However, (A) is not a necessary assumption. Even if a certain grocery store charged higher prices for poultry during the period, this fact would probably not be statistically significant in light of the much lower national average—especially if that store were located in another state and therefore did not compete with the three chains.

(B) actually serves to weaken the argument. Given (B), the greater the number of other grocery stores in the same state the more likely that these other stores also charged high prices for poultry. This fact would in turn help refute the claim that the three chains were motivated by any concern other than to compete effectively against other stores in the state.

(D) is not relevant to the argument, which is concerned with poultry prices charged by the three chains compared to poultry prices in other states, not compared to prices of other meats.

(E) actually serves to weaken the argument. The more competitors, the less likely these three chains together hold a statewide poultry monopoly. (Monopolists are more likely to charge whatever price they wish for their products.)

[peter.p.81]

The official answer is .C But I don't understand why? Can anyone explain