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Finding the Fourth Proportional to 559.42, 772.70 and 420.20

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Solution

The fourth proportional to 559.42, 772.70 and 420.20 is: 580.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    559.42 : 772.70 = 420.20 : x
  2. Step 2: Convert to fraction form
    559.42/772.70 = 420.20/x
  3. Step 3: Cross multiply
    559.42x = 772.70 × 420.20
  4. Step 4: Simplify right side
    559.42x = 324,688.54
  5. Step 5: Solve for x
    x = 324,688.54/559.42
  6. Step 6: Final answer
    x = 580.40

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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.