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Finding the Fourth Proportional to 260.85, 390.77 and 138.81

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Solution

The fourth proportional to 260.85, 390.77 and 138.81 is: 207.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    260.85 : 390.77 = 138.81 : x
  2. Step 2: Convert to fraction form
    260.85/390.77 = 138.81/x
  3. Step 3: Cross multiply
    260.85x = 390.77 × 138.81
  4. Step 4: Simplify right side
    260.85x = 54,242.09
  5. Step 5: Solve for x
    x = 54,242.09/260.85
  6. Step 6: Final answer
    x = 207.94

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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.