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Finding the Fourth Proportional to 670.30, 1,005.32 and 426.49

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Solution

The fourth proportional to 670.30, 1,005.32 and 426.49 is: 639.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    670.30 : 1,005.32 = 426.49 : x
  2. Step 2: Convert to fraction form
    670.30/1,005.32 = 426.49/x
  3. Step 3: Cross multiply
    670.30x = 1,005.32 × 426.49
  4. Step 4: Simplify right side
    670.30x = 428,756.79
  5. Step 5: Solve for x
    x = 428,756.79/670.30
  6. Step 6: Final answer
    x = 639.65

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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.