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Finding the Fourth Proportional to 518.74, 715.78 and 308.91

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Solution

The fourth proportional to 518.74, 715.78 and 308.91 is: 426.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    518.74 : 715.78 = 308.91 : x
  2. Step 2: Convert to fraction form
    518.74/715.78 = 308.91/x
  3. Step 3: Cross multiply
    518.74x = 715.78 × 308.91
  4. Step 4: Simplify right side
    518.74x = 221,113.80
  5. Step 5: Solve for x
    x = 221,113.80/518.74
  6. Step 6: Final answer
    x = 426.25

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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.