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Finding the Fourth Proportional to 515.75, 711.77 and 305.90

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Solution

The fourth proportional to 515.75, 711.77 and 305.90 is: 422.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    515.75 : 711.77 = 305.90 : x
  2. Step 2: Convert to fraction form
    515.75/711.77 = 305.90/x
  3. Step 3: Cross multiply
    515.75x = 711.77 × 305.90
  4. Step 4: Simplify right side
    515.75x = 217,725.35
  5. Step 5: Solve for x
    x = 217,725.35/515.75
  6. Step 6: Final answer
    x = 422.15

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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.