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Finding the Fourth Proportional to 1,318.37, 1,819.35 and 728.90

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Solution

The fourth proportional to 1,318.37, 1,819.35 and 728.90 is: 1,005.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,318.37 : 1,819.35 = 728.90 : x
  2. Step 2: Convert to fraction form
    1,318.37/1,819.35 = 728.90/x
  3. Step 3: Cross multiply
    1,318.37x = 1,819.35 × 728.90
  4. Step 4: Simplify right side
    1,318.37x = 1,326,124.22
  5. Step 5: Solve for x
    x = 1,326,124.22/1,318.37
  6. Step 6: Final answer
    x = 1,005.88

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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.