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Finding the Fourth Proportional to 540.81, 812.12 and 420.05

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Solution

The fourth proportional to 540.81, 812.12 and 420.05 is: 630.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    540.81 : 812.12 = 420.05 : x
  2. Step 2: Convert to fraction form
    540.81/812.12 = 420.05/x
  3. Step 3: Cross multiply
    540.81x = 812.12 × 420.05
  4. Step 4: Simplify right side
    540.81x = 341,130.94
  5. Step 5: Solve for x
    x = 341,130.94/540.81
  6. Step 6: Final answer
    x = 630.78

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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.