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Finding the Fourth Proportional to 613.74, 920.93 and 408.40

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Solution

The fourth proportional to 613.74, 920.93 and 408.40 is: 612.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    613.74 : 920.93 = 408.40 : x
  2. Step 2: Convert to fraction form
    613.74/920.93 = 408.40/x
  3. Step 3: Cross multiply
    613.74x = 920.93 × 408.40
  4. Step 4: Simplify right side
    613.74x = 376,107.81
  5. Step 5: Solve for x
    x = 376,107.81/613.74
  6. Step 6: Final answer
    x = 612.81

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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.