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Finding the Fourth Proportional to 818.60, 1,128.91 and 609.30

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Solution

The fourth proportional to 818.60, 1,128.91 and 609.30 is: 840.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    818.60 : 1,128.91 = 609.30 : x
  2. Step 2: Convert to fraction form
    818.60/1,128.91 = 609.30/x
  3. Step 3: Cross multiply
    818.60x = 1,128.91 × 609.30
  4. Step 4: Simplify right side
    818.60x = 687,844.86
  5. Step 5: Solve for x
    x = 687,844.86/818.60
  6. Step 6: Final answer
    x = 840.27

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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.