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Finding the Fourth Proportional to 946.80, 1,420.20 and 398.85

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Solution

The fourth proportional to 946.80, 1,420.20 and 398.85 is: 598.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    946.80 : 1,420.20 = 398.85 : x
  2. Step 2: Convert to fraction form
    946.80/1,420.20 = 398.85/x
  3. Step 3: Cross multiply
    946.80x = 1,420.20 × 398.85
  4. Step 4: Simplify right side
    946.80x = 566,446.77
  5. Step 5: Solve for x
    x = 566,446.77/946.80
  6. Step 6: Final answer
    x = 598.28

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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.