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Finding the Fourth Proportional to 1,999.78, 2,999.57 and 1,939.64

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Solution

The fourth proportional to 1,999.78, 2,999.57 and 1,939.64 is: 2,909.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,999.78 : 2,999.57 = 1,939.64 : x
  2. Step 2: Convert to fraction form
    1,999.78/2,999.57 = 1,939.64/x
  3. Step 3: Cross multiply
    1,999.78x = 2,999.57 × 1,939.64
  4. Step 4: Simplify right side
    1,999.78x = 5,818,061.26
  5. Step 5: Solve for x
    x = 5,818,061.26/1,999.78
  6. Step 6: Final answer
    x = 2,909.35

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.