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Finding the Fourth Proportional to 515, 710.78 and 308.12

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Solution

The fourth proportional to 515, 710.78 and 308.12 is: 425.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    515 : 710.78 = 308.12 : x
  2. Step 2: Convert to fraction form
    515/710.78 = 308.12/x
  3. Step 3: Cross multiply
    515x = 710.78 × 308.12
  4. Step 4: Simplify right side
    515x = 219,005.53
  5. Step 5: Solve for x
    x = 219,005.53/515
  6. Step 6: Final answer
    x = 425.25

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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.