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Finding the Fourth Proportional to 670.40, 1,005.98 and 285.64

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Solution

The fourth proportional to 670.40, 1,005.98 and 285.64 is: 428.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    670.40 : 1,005.98 = 285.64 : x
  2. Step 2: Convert to fraction form
    670.40/1,005.98 = 285.64/x
  3. Step 3: Cross multiply
    670.40x = 1,005.98 × 285.64
  4. Step 4: Simplify right side
    670.40x = 287,348.13
  5. Step 5: Solve for x
    x = 287,348.13/670.40
  6. Step 6: Final answer
    x = 428.62

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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.