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Finding the Fourth Proportional to 518.79, 715.94 and 309

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Solution

The fourth proportional to 518.79, 715.94 and 309 is: 426.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    518.79 : 715.94 = 309 : x
  2. Step 2: Convert to fraction form
    518.79/715.94 = 309/x
  3. Step 3: Cross multiply
    518.79x = 715.94 × 309
  4. Step 4: Simplify right side
    518.79x = 221,225.46
  5. Step 5: Solve for x
    x = 221,225.46/518.79
  6. Step 6: Final answer
    x = 426.43

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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.