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Finding the Fourth Proportional to 515.79, 711.78 and 279.73

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Solution

The fourth proportional to 515.79, 711.78 and 279.73 is: 386.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    515.79 : 711.78 = 279.73 : x
  2. Step 2: Convert to fraction form
    515.79/711.78 = 279.73/x
  3. Step 3: Cross multiply
    515.79x = 711.78 × 279.73
  4. Step 4: Simplify right side
    515.79x = 199,105.24
  5. Step 5: Solve for x
    x = 199,105.24/515.79
  6. Step 6: Final answer
    x = 386.02

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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.