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Finding the Fourth Proportional to 515.72, 711.70 and 305.91

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Solution

The fourth proportional to 515.72, 711.70 and 305.91 is: 422.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    515.72 : 711.70 = 305.91 : x
  2. Step 2: Convert to fraction form
    515.72/711.70 = 305.91/x
  3. Step 3: Cross multiply
    515.72x = 711.70 × 305.91
  4. Step 4: Simplify right side
    515.72x = 217,715.38
  5. Step 5: Solve for x
    x = 217,715.38/515.72
  6. Step 6: Final answer
    x = 422.16

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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.