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Finding the Fourth Proportional to 670.43, 1,005.90 and 280.64

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Solution

The fourth proportional to 670.43, 1,005.90 and 280.64 is: 421.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    670.43 : 1,005.90 = 280.64 : x
  2. Step 2: Convert to fraction form
    670.43/1,005.90 = 280.64/x
  3. Step 3: Cross multiply
    670.43x = 1,005.90 × 280.64
  4. Step 4: Simplify right side
    670.43x = 282,295.78
  5. Step 5: Solve for x
    x = 282,295.78/670.43
  6. Step 6: Final answer
    x = 421.07

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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.