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Finding the Fourth Proportional to 731.28, 1,009.16 and 420.72

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Solution

The fourth proportional to 731.28, 1,009.16 and 420.72 is: 580.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    731.28 : 1,009.16 = 420.72 : x
  2. Step 2: Convert to fraction form
    731.28/1,009.16 = 420.72/x
  3. Step 3: Cross multiply
    731.28x = 1,009.16 × 420.72
  4. Step 4: Simplify right side
    731.28x = 424,573.80
  5. Step 5: Solve for x
    x = 424,573.80/731.28
  6. Step 6: Final answer
    x = 580.59

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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.