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Finding the Fourth Proportional to 769.72, 1,062.18 and 420.42

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Solution

The fourth proportional to 769.72, 1,062.18 and 420.42 is: 580.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    769.72 : 1,062.18 = 420.42 : x
  2. Step 2: Convert to fraction form
    769.72/1,062.18 = 420.42/x
  3. Step 3: Cross multiply
    769.72x = 1,062.18 × 420.42
  4. Step 4: Simplify right side
    769.72x = 446,561.72
  5. Step 5: Solve for x
    x = 446,561.72/769.72
  6. Step 6: Final answer
    x = 580.16

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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.