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Finding the Fourth Proportional to 1,081.20, 1,621.80 and 756.72

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Solution

The fourth proportional to 1,081.20, 1,621.80 and 756.72 is: 1,135.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,081.20 : 1,621.80 = 756.72 : x
  2. Step 2: Convert to fraction form
    1,081.20/1,621.80 = 756.72/x
  3. Step 3: Cross multiply
    1,081.20x = 1,621.80 × 756.72
  4. Step 4: Simplify right side
    1,081.20x = 1,227,248.50
  5. Step 5: Solve for x
    x = 1,227,248.50/1,081.20
  6. Step 6: Final answer
    x = 1,135.08

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.