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Finding the Fourth Proportional to 661.78, 911.28 and 625.06

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Solution

The fourth proportional to 661.78, 911.28 and 625.06 is: 860.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    661.78 : 911.28 = 625.06 : x
  2. Step 2: Convert to fraction form
    661.78/911.28 = 625.06/x
  3. Step 3: Cross multiply
    661.78x = 911.28 × 625.06
  4. Step 4: Simplify right side
    661.78x = 569,604.68
  5. Step 5: Solve for x
    x = 569,604.68/661.78
  6. Step 6: Final answer
    x = 860.72

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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.