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Finding the Fourth Proportional to 730.50, 1,008.21 and 420.18

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Solution

The fourth proportional to 730.50, 1,008.21 and 420.18 is: 579.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    730.50 : 1,008.21 = 420.18 : x
  2. Step 2: Convert to fraction form
    730.50/1,008.21 = 420.18/x
  3. Step 3: Cross multiply
    730.50x = 1,008.21 × 420.18
  4. Step 4: Simplify right side
    730.50x = 423,629.68
  5. Step 5: Solve for x
    x = 423,629.68/730.50
  6. Step 6: Final answer
    x = 579.92

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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.