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Finding the Fourth Proportional to 728.48, 1,090.69 and 419.87

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Solution

The fourth proportional to 728.48, 1,090.69 and 419.87 is: 628.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    728.48 : 1,090.69 = 419.87 : x
  2. Step 2: Convert to fraction form
    728.48/1,090.69 = 419.87/x
  3. Step 3: Cross multiply
    728.48x = 1,090.69 × 419.87
  4. Step 4: Simplify right side
    728.48x = 457,948.01
  5. Step 5: Solve for x
    x = 457,948.01/728.48
  6. Step 6: Final answer
    x = 628.63

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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.