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Finding the Fourth Proportional to 260.88, 390.96 and 209.64

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Solution

The fourth proportional to 260.88, 390.96 and 209.64 is: 314.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    260.88 : 390.96 = 209.64 : x
  2. Step 2: Convert to fraction form
    260.88/390.96 = 209.64/x
  3. Step 3: Cross multiply
    260.88x = 390.96 × 209.64
  4. Step 4: Simplify right side
    260.88x = 81,960.85
  5. Step 5: Solve for x
    x = 81,960.85/260.88
  6. Step 6: Final answer
    x = 314.17

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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.