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Finding the Fourth Proportional to 870.43, 1,305.12 and 342.70

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Solution

The fourth proportional to 870.43, 1,305.12 and 342.70 is: 513.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    870.43 : 1,305.12 = 342.70 : x
  2. Step 2: Convert to fraction form
    870.43/1,305.12 = 342.70/x
  3. Step 3: Cross multiply
    870.43x = 1,305.12 × 342.70
  4. Step 4: Simplify right side
    870.43x = 447,266.17
  5. Step 5: Solve for x
    x = 447,266.17/870.43
  6. Step 6: Final answer
    x = 513.85

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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.