Researchers studying long-term changes in regional mouse populations have found that by focusing on the populations of a rare but...

Owning the Dataset

Understanding Source A: Text Source - Research Study

• Summary: Research study establishes Species X as a reliable indicator for total mouse populations, with specific examples showing CV region growth and EW region decline between 1990-2005

Understanding Source B: Data Tables - Species X Population Data

• Table Contents:
  • Two tables presenting Species X population data across six regions (CV, EW, IQ, JR, PS, TY)
  • Three time periods covered: 1960, 1975, 1990
  • First table: Absolute population numbers
  • Second table: Species X as percentage of total mouse population
• Key Patterns:
  • Species X populations range from 20,760 (JR, 1990) to 1,859,460 (IQ, 1960)
  • IQ region: Dramatic continuous decline: 1,859,460 → 928,340 → 465,610
  • EW region: Stability then growth: 393,260 → 392,080 → 964,020
  • Most regions show declining percentages over time
• Species Rarity Confirmed: Never exceeds 4% of total mouse population (highest: TY at 3.356% in 1960)
• EW Growth Pattern: Only region showing significant growth by 1990, more than doubling between 1975-1990
• Continuous Coverage: Source B data ends in 1990, exactly where Source A's timeframe begins (1990-2005), providing 45-year coverage
• Regional Population Peaks: EW shows opposite trends - growth through 1990 in Source B, then 52% decline after 1990 in Source A

• Summary: Historical data reveals highly variable Species X populations across regions, with most experiencing declines except EW which grew dramatically before 1990, confirming Species X's rarity and validating its use as an indicator species

Overall Summary

• Data Coverage: Nearly half a century of continuous Species X population data (1960-2005)
• Rarity Confirmation: Species X consistently represents less than 4% of total mouse populations
• EW Population Peak: Around 1990 - growing dramatically before then declining sharply after
• Accuracy Level: Percentage variation (0.255% to 3.356%) explains why estimates are ""fairly accurate"" rather than precise
• Methodology Validation: Sources together validate using this rare species to estimate total mouse populations across regions

Question Analysis

• Task: Evaluate three statements about the total mouse population of the TY region across different time periods
• Requirements:
  • Must evaluate each statement as Yes or No
  • Focus specifically on TY region
  • Statements concern TOTAL mouse population, not just Species X
  • Need to calculate total populations from Species X data and percentages
• Answer Type: Numerical calculation and verification of claims about population changes

Connecting to Our Passage Analysis

• Calculation Required: The analysis doesn't directly address total mouse populations for TY region - must calculate from Species X population and percentage data in Source B tables
• Formula: Total Population = Species X Population ÷ (Percentage ÷ 100)
• Source: Cannot answer from analysis alone - requires calculation using Source B data

Extracting Relevant Findings

• TY Region Data from Source B:
  • Species X populations: 1960: 947,630; 1975: 144,520; 1990: 968,460
  • Percentages: 1960: 3.356%; 1975: 0.351%; 1990: 2.051%

Statement 1 Evaluation

• Question: Did TY's total mouse population change more between 1960-1975 than between 1975-1990?
• Calculations:
  • 1960 total: 947,630 ÷ 0.03356 = 28,236,423
  • 1975 total: 144,520 ÷ 0.00351 = 41,188,034
  • 1990 total: 968,460 ÷ 0.02051 = 47,219,893
• Change 1960-1975: From 28,236,423 to 41,188,034 = increase of 12,951,611
• Change 1975-1990: From 41,188,034 to 47,219,893 = increase of 6,031,859
• Result: 12,951,611 > 6,031,859
• YES - The population changed more (~13 million increase) from 1960-1975 than from 1975-1990 (~6 million increase)

Statement 2 Evaluation

• Question: Was TY's total mouse population 47 million in 1990 when rounded to the nearest million?
• 1990 total population: 968,460 ÷ 0.02051 = 47,219,893
• Rounded to nearest million: 47,000,000
• YES - The 1990 population of 47,219,893 rounds to 47 million

Statement 3 Evaluation

• Question: Did TY's total mouse population decrease from 1975 to 1990?
• 1975 population: 41,188,034
• 1990 population: 47,219,893
• Comparison: 47,219,893 > 41,188,034 (increased, not decreased)
• NO - The population INCREASED from 41.2 million to 47.2 million, not fell

Calculation Verification

• Formula Check: Species X population divided by percentage as decimal
  • 1960: 947,630 ÷ 0.03356 = 28,236,423
  • 1975: 144,520 ÷ 0.00351 = 41,188,034
  • 1990: 968,460 ÷ 0.02051 = 47,219,893
• All three statements evaluated using calculated totals

• Final Answer: Yes, Yes, No