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Finding the Fourth Proportional to 261.39, 361.09 and 209.28

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Solution

The fourth proportional to 261.39, 361.09 and 209.28 is: 289.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    261.39 : 361.09 = 209.28 : x
  2. Step 2: Convert to fraction form
    261.39/361.09 = 209.28/x
  3. Step 3: Cross multiply
    261.39x = 361.09 × 209.28
  4. Step 4: Simplify right side
    261.39x = 75,568.39
  5. Step 5: Solve for x
    x = 75,568.39/261.39
  6. Step 6: Final answer
    x = 289.10

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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.