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Finding the Fourth Proportional to 613.40, 920.10 and 491.90

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Solution

The fourth proportional to 613.40, 920.10 and 491.90 is: 737.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    613.40 : 920.10 = 491.90 : x
  2. Step 2: Convert to fraction form
    613.40/920.10 = 491.90/x
  3. Step 3: Cross multiply
    613.40x = 920.10 × 491.90
  4. Step 4: Simplify right side
    613.40x = 452,597.19
  5. Step 5: Solve for x
    x = 452,597.19/613.40
  6. Step 6: Final answer
    x = 737.85

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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.