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Finding the Fourth Proportional to 731.20, 1,009.05 and 399.62

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Solution

The fourth proportional to 731.20, 1,009.05 and 399.62 is: 551.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    731.20 : 1,009.05 = 399.62 : x
  2. Step 2: Convert to fraction form
    731.20/1,009.05 = 399.62/x
  3. Step 3: Cross multiply
    731.20x = 1,009.05 × 399.62
  4. Step 4: Simplify right side
    731.20x = 403,232.04
  5. Step 5: Solve for x
    x = 403,232.04/731.20
  6. Step 6: Final answer
    x = 551.47

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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.