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Finding the Fourth Proportional to 408.95, 613.42 and 100.80

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Solution

The fourth proportional to 408.95, 613.42 and 100.80 is: 151.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    408.95 : 613.42 = 100.80 : x
  2. Step 2: Convert to fraction form
    408.95/613.42 = 100.80/x
  3. Step 3: Cross multiply
    408.95x = 613.42 × 100.80
  4. Step 4: Simplify right side
    408.95x = 61,834.78
  5. Step 5: Solve for x
    x = 61,834.78/408.95
  6. Step 6: Final answer
    x = 151.20

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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.