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Finding the Fourth Proportional to 670.92, 1,005.78 and 345.72

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Solution

The fourth proportional to 670.92, 1,005.78 and 345.72 is: 518.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    670.92 : 1,005.78 = 345.72 : x
  2. Step 2: Convert to fraction form
    670.92/1,005.78 = 345.72/x
  3. Step 3: Cross multiply
    670.92x = 1,005.78 × 345.72
  4. Step 4: Simplify right side
    670.92x = 347,718.26
  5. Step 5: Solve for x
    x = 347,718.26/670.92
  6. Step 6: Final answer
    x = 518.27

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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.