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Finding the Fourth Proportional to 628.78, 867.12 and 407.62

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Solution

The fourth proportional to 628.78, 867.12 and 407.62 is: 562.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    628.78 : 867.12 = 407.62 : x
  2. Step 2: Convert to fraction form
    628.78/867.12 = 407.62/x
  3. Step 3: Cross multiply
    628.78x = 867.12 × 407.62
  4. Step 4: Simplify right side
    628.78x = 353,455.45
  5. Step 5: Solve for x
    x = 353,455.45/628.78
  6. Step 6: Final answer
    x = 562.13

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.