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Finding the Fourth Proportional to 870.98, 1,306.43 and 285.91

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Solution

The fourth proportional to 870.98, 1,306.43 and 285.91 is: 428.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    870.98 : 1,306.43 = 285.91 : x
  2. Step 2: Convert to fraction form
    870.98/1,306.43 = 285.91/x
  3. Step 3: Cross multiply
    870.98x = 1,306.43 × 285.91
  4. Step 4: Simplify right side
    870.98x = 373,517.78
  5. Step 5: Solve for x
    x = 373,517.78/870.98
  6. Step 6: Final answer
    x = 428.85

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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.