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Finding the Fourth Proportional to 514.81, 771.75 and 428.85

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Solution

The fourth proportional to 514.81, 771.75 and 428.85 is: 642.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    514.81 : 771.75 = 428.85 : x
  2. Step 2: Convert to fraction form
    514.81/771.75 = 428.85/x
  3. Step 3: Cross multiply
    514.81x = 771.75 × 428.85
  4. Step 4: Simplify right side
    514.81x = 330,964.99
  5. Step 5: Solve for x
    x = 330,964.99/514.81
  6. Step 6: Final answer
    x = 642.89

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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.