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Finding the Fourth Proportional to 260.50, 390.30 and 209.20

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Solution

The fourth proportional to 260.50, 390.30 and 209.20 is: 313.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    260.50 : 390.30 = 209.20 : x
  2. Step 2: Convert to fraction form
    260.50/390.30 = 209.20/x
  3. Step 3: Cross multiply
    260.50x = 390.30 × 209.20
  4. Step 4: Simplify right side
    260.50x = 81,650.76
  5. Step 5: Solve for x
    x = 81,650.76/260.50
  6. Step 6: Final answer
    x = 313.44

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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.