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Finding the Fourth Proportional to 670.28, 1,003.47 and 391.79

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Solution

The fourth proportional to 670.28, 1,003.47 and 391.79 is: 586.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    670.28 : 1,003.47 = 391.79 : x
  2. Step 2: Convert to fraction form
    670.28/1,003.47 = 391.79/x
  3. Step 3: Cross multiply
    670.28x = 1,003.47 × 391.79
  4. Step 4: Simplify right side
    670.28x = 393,144.49
  5. Step 5: Solve for x
    x = 393,144.49/670.28
  6. Step 6: Final answer
    x = 586.54

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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.