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Finding the Fourth Proportional to 680.56, 1,018.50 and 420.46

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Solution

The fourth proportional to 680.56, 1,018.50 and 420.46 is: 629.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    680.56 : 1,018.50 = 420.46 : x
  2. Step 2: Convert to fraction form
    680.56/1,018.50 = 420.46/x
  3. Step 3: Cross multiply
    680.56x = 1,018.50 × 420.46
  4. Step 4: Simplify right side
    680.56x = 428,238.51
  5. Step 5: Solve for x
    x = 428,238.51/680.56
  6. Step 6: Final answer
    x = 629.24

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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.