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Finding the Fourth Proportional to 511.78, 705.90 and 315.40

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Solution

The fourth proportional to 511.78, 705.90 and 315.40 is: 435.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    511.78 : 705.90 = 315.40 : x
  2. Step 2: Convert to fraction form
    511.78/705.90 = 315.40/x
  3. Step 3: Cross multiply
    511.78x = 705.90 × 315.40
  4. Step 4: Simplify right side
    511.78x = 222,640.86
  5. Step 5: Solve for x
    x = 222,640.86/511.78
  6. Step 6: Final answer
    x = 435.03

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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.