For each of the last six years, the table shows the price, in Banglade

Question

For each of the last six years, the table shows the price, in Bangladeshi taka, of one unit for each of 4 types of items—ltems A through D. The price index shown in the table is the sum of the prices of certain numbers of units of each type of item. For instance, the price index for each year includes the cost of 20 units of Item A.

Year 
 A 
 B 
 C 
 D 
 Price
Index 
 
  1 
 3 
 10 
 9 
 3 
 345 
 
  2 
 3 
 12 
 10 
 1 
 347 
 
  3 
 5 
 12 
 8 
 5 
 407 
 
  4 
 8 
 10 
 6 
 5 
 415 
 
  5 
 8 
 10 
 7 
 4 
 420 
 
  6 
 6 
 8 
 5 
 6 
 358

Bismuth83 · Accepted Answer

1. The question asks us to analyze the table and check the statements to see whether they are true or false.

2. The years in which the Item B prices were highest were also the years for which the price index was least. Item B its highest price - 12 - during years 2 and 3. During this time the price index was 347 and 407, respectively. However, the two lowest years for the price index had values of 345 and 347. So, the statement is false.

3. The prices of Item A were positively correlated with the price index. Positively correlated factors are when one factor increases, the other tends to do the same and the same goes for decreasing. For years 1-5, A gradually increases and the same happens with the price index. From year 5 to 6, A decreases and the price index does the same. So, the statement is true.

4. The prices of Item C and the prices of Item D were positively correlated. We have a counter-example by considering years 1-2, for example. Here, C increases, however, D decreases. So, the statement is false.

Show Spoiler

Attachment:

PriceGraph1.jpg [ 21.11 KiB | Viewed 6832 times ]

Attachment:

PriceGraph2.jpg [ 19.56 KiB | Viewed 6752 times ]

SirSanguine · Answer

The second bit is the challenging one for me , here's how you can tackle the correlations when its not veru obvious.

M1. If the values above the average row of first quantity are smaller than the average and if the values below the average row of first quantity are larger, then there is positive correlation. This is because the sorted dataset also has smaller values above this average row since we sorted in ascending order.

Above average values should be larger than below average.

M2. Make a scatter plot an try rough curve fitting if you get positive slope line +ve correlation if downward line negative correlation.

ManifestDreamMBA · Answer

Can someone please help with the sorting option, it's not available?

Bunuel · Answer

Fixed the issue. Hope now it's OK.

ManifestDreamMBA · Answer

Thanks Bunuel! Yes, works all fine

For each of the last six years, the table shows the price, in Banglade

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

Yes	No
		The years in which the Item B prices were highest were also the years for which the price index was least.
		The prices of Item A were positively correlated with the price index.
		The prices of Item C and the prices of Item D were positively correlated.

GMAT Graphs and Tables (G&T) Questions

For each of the last six years, the table shows the price, in Banglade

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards