Dear GMAT club members. I have a very general question on averages (arithmetic means). I worked through a number of OG guide problems as well as Manhattan Word Problem sets that deal with arithmetic averages.
Is my conclusion below correct:
Assume you have two groups of data, say one set of data for males and one set of data for females. If you have the average for the total group, and you are given the average for one group (say males) it is not possible to determine the average of the second group without knowing anything on the numbers in the groups (either be it total numbers or ratios).
For example:
Question 1:
(note this question is one of the problem sets in manhattan gmat guides)
A charitable association sold an average of 66 raffle tickets per member. Among the female members, the average was 70 raffle tickets. The male to female ratio of the association if 1:2. What was the average number of tickets sold by the male members of the association?
If the ratio between males:females were ommitted, it is impossible to deduce the average of the tickets sold by the male group. Is my assumption correct?
Question 2:
(note this question comes out of the OG 2015 edition), I actually found this question extremely complex. But having studied Manhattan guides, I realised that you need both statements together(one dealing with the average of one group, and the other dealing with a certain quantitative indicator for the group) to answer this qestion. Is my reasoning correct?
At a certain company, a test was given to a group of men and women seeking promotions. If the average score for the group was 80, was the average score for the women greater than 85?
1. The average score for the men was less than 75.
2. The group consisted of more men than women
I notice that the GMAT loves playing with this idea on data sufficiency problems so I was just hoping to get some insight from all you bright people on here:-)![]()
Is my conclusion below correct:
Assume you have two groups of data, say one set of data for males and one set of data for females. If you have the average for the total group, and you are given the average for one group (say males) it is not possible to determine the average of the second group without knowing anything on the numbers in the groups (either be it total numbers or ratios).
For example:
Question 1:
(note this question is one of the problem sets in manhattan gmat guides)
A charitable association sold an average of 66 raffle tickets per member. Among the female members, the average was 70 raffle tickets. The male to female ratio of the association if 1:2. What was the average number of tickets sold by the male members of the association?
If the ratio between males:females were ommitted, it is impossible to deduce the average of the tickets sold by the male group. Is my assumption correct?
Question 2:
(note this question comes out of the OG 2015 edition), I actually found this question extremely complex. But having studied Manhattan guides, I realised that you need both statements together(one dealing with the average of one group, and the other dealing with a certain quantitative indicator for the group) to answer this qestion. Is my reasoning correct?
At a certain company, a test was given to a group of men and women seeking promotions. If the average score for the group was 80, was the average score for the women greater than 85?
1. The average score for the men was less than 75.
2. The group consisted of more men than women
I notice that the GMAT loves playing with this idea on data sufficiency problems so I was just hoping to get some insight from all you bright people on here:-)
