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Finding the Fourth Proportional to 613.05, 917.42 and 420.81

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Solution

The fourth proportional to 613.05, 917.42 and 420.81 is: 629.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    613.05 : 917.42 = 420.81 : x
  2. Step 2: Convert to fraction form
    613.05/917.42 = 420.81/x
  3. Step 3: Cross multiply
    613.05x = 917.42 × 420.81
  4. Step 4: Simplify right side
    613.05x = 386,057.41
  5. Step 5: Solve for x
    x = 386,057.41/613.05
  6. Step 6: Final answer
    x = 629.73

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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.