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Finding the Fourth Proportional to 815.72, 1,216.42 and 727.20

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Solution

The fourth proportional to 815.72, 1,216.42 and 727.20 is: 1,084.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    815.72 : 1,216.42 = 727.20 : x
  2. Step 2: Convert to fraction form
    815.72/1,216.42 = 727.20/x
  3. Step 3: Cross multiply
    815.72x = 1,216.42 × 727.20
  4. Step 4: Simplify right side
    815.72x = 884,580.62
  5. Step 5: Solve for x
    x = 884,580.62/815.72
  6. Step 6: Final answer
    x = 1,084.42

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.