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Finding the Fourth Proportional to 518.88, 715.88 and 309

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Solution

The fourth proportional to 518.88, 715.88 and 309 is: 426.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    518.88 : 715.88 = 309 : x
  2. Step 2: Convert to fraction form
    518.88/715.88 = 309/x
  3. Step 3: Cross multiply
    518.88x = 715.88 × 309
  4. Step 4: Simplify right side
    518.88x = 221,206.92
  5. Step 5: Solve for x
    x = 221,206.92/518.88
  6. Step 6: Final answer
    x = 426.32

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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.