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Finding the Fourth Proportional to 206.63, 309.75 and 78.29

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Solution

The fourth proportional to 206.63, 309.75 and 78.29 is: 117.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    206.63 : 309.75 = 78.29 : x
  2. Step 2: Convert to fraction form
    206.63/309.75 = 78.29/x
  3. Step 3: Cross multiply
    206.63x = 309.75 × 78.29
  4. Step 4: Simplify right side
    206.63x = 24,248.78
  5. Step 5: Solve for x
    x = 24,248.78/206.63
  6. Step 6: Final answer
    x = 117.36

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.