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Finding the Fourth Proportional to 520.97, 781.47 and 257.67

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Solution

The fourth proportional to 520.97, 781.47 and 257.67 is: 386.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    520.97 : 781.47 = 257.67 : x
  2. Step 2: Convert to fraction form
    520.97/781.47 = 257.67/x
  3. Step 3: Cross multiply
    520.97x = 781.47 × 257.67
  4. Step 4: Simplify right side
    520.97x = 201,361.37
  5. Step 5: Solve for x
    x = 201,361.37/520.97
  6. Step 6: Final answer
    x = 386.52

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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.