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Finding the Fourth Proportional to 515.68, 711.72 and 305.86

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Solution

The fourth proportional to 515.68, 711.72 and 305.86 is: 422.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    515.68 : 711.72 = 305.86 : x
  2. Step 2: Convert to fraction form
    515.68/711.72 = 305.86/x
  3. Step 3: Cross multiply
    515.68x = 711.72 × 305.86
  4. Step 4: Simplify right side
    515.68x = 217,686.68
  5. Step 5: Solve for x
    x = 217,686.68/515.68
  6. Step 6: Final answer
    x = 422.14

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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.