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Finding the Fourth Proportional to 261.78, 360.87 and 209.49

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Solution

The fourth proportional to 261.78, 360.87 and 209.49 is: 288.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    261.78 : 360.87 = 209.49 : x
  2. Step 2: Convert to fraction form
    261.78/360.87 = 209.49/x
  3. Step 3: Cross multiply
    261.78x = 360.87 × 209.49
  4. Step 4: Simplify right side
    261.78x = 75,598.66
  5. Step 5: Solve for x
    x = 75,598.66/261.78
  6. Step 6: Final answer
    x = 288.79

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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.