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Finding the Fourth Proportional to 515.16, 709.56 and 389.61

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Solution

The fourth proportional to 515.16, 709.56 and 389.61 is: 536.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    515.16 : 709.56 = 389.61 : x
  2. Step 2: Convert to fraction form
    515.16/709.56 = 389.61/x
  3. Step 3: Cross multiply
    515.16x = 709.56 × 389.61
  4. Step 4: Simplify right side
    515.16x = 276,451.67
  5. Step 5: Solve for x
    x = 276,451.67/515.16
  6. Step 6: Final answer
    x = 536.63

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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.