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Finding the Fourth Proportional to 408.55, 611.46 and 340.21

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Solution

The fourth proportional to 408.55, 611.46 and 340.21 is: 509.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    408.55 : 611.46 = 340.21 : x
  2. Step 2: Convert to fraction form
    408.55/611.46 = 340.21/x
  3. Step 3: Cross multiply
    408.55x = 611.46 × 340.21
  4. Step 4: Simplify right side
    408.55x = 208,024.81
  5. Step 5: Solve for x
    x = 208,024.81/408.55
  6. Step 6: Final answer
    x = 509.18

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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.