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Finding the Fourth Proportional to 405.38, 606.85 and 260.80

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Solution

The fourth proportional to 405.38, 606.85 and 260.80 is: 390.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    405.38 : 606.85 = 260.80 : x
  2. Step 2: Convert to fraction form
    405.38/606.85 = 260.80/x
  3. Step 3: Cross multiply
    405.38x = 606.85 × 260.80
  4. Step 4: Simplify right side
    405.38x = 158,266.48
  5. Step 5: Solve for x
    x = 158,266.48/405.38
  6. Step 6: Final answer
    x = 390.42

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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.