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Finding the Fourth Proportional to 630.86, 870.44 and 420.80

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Solution

The fourth proportional to 630.86, 870.44 and 420.80 is: 580.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    630.86 : 870.44 = 420.80 : x
  2. Step 2: Convert to fraction form
    630.86/870.44 = 420.80/x
  3. Step 3: Cross multiply
    630.86x = 870.44 × 420.80
  4. Step 4: Simplify right side
    630.86x = 366,281.15
  5. Step 5: Solve for x
    x = 366,281.15/630.86
  6. Step 6: Final answer
    x = 580.61

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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.