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Finding the Fourth Proportional to 1,539, 2,123.84 and 840.39

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Solution

The fourth proportional to 1,539, 2,123.84 and 840.39 is: 1,159.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,539 : 2,123.84 = 840.39 : x
  2. Step 2: Convert to fraction form
    1,539/2,123.84 = 840.39/x
  3. Step 3: Cross multiply
    1,539x = 2,123.84 × 840.39
  4. Step 4: Simplify right side
    1,539x = 1,784,849.70
  5. Step 5: Solve for x
    x = 1,784,849.70/1,539
  6. Step 6: Final answer
    x = 1,159.75

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.