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Finding the Fourth Proportional to 469.86, 649.86 and 420.72

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Solution

The fourth proportional to 469.86, 649.86 and 420.72 is: 581.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    469.86 : 649.86 = 420.72 : x
  2. Step 2: Convert to fraction form
    469.86/649.86 = 420.72/x
  3. Step 3: Cross multiply
    469.86x = 649.86 × 420.72
  4. Step 4: Simplify right side
    469.86x = 273,409.10
  5. Step 5: Solve for x
    x = 273,409.10/469.86
  6. Step 6: Final answer
    x = 581.89

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.