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Finding the Fourth Proportional to 728.60, 1,091.16 and 419.81

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Solution

The fourth proportional to 728.60, 1,091.16 and 419.81 is: 628.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.60 : 1,091.16 = 419.81 : x
  2. Step 2: Convert to fraction form
    728.60/1,091.16 = 419.81/x
  3. Step 3: Cross multiply
    728.60x = 1,091.16 × 419.81
  4. Step 4: Simplify right side
    728.60x = 458,074.42
  5. Step 5: Solve for x
    x = 458,074.42/728.60
  6. Step 6: Final answer
    x = 628.70

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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.