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Finding the Fourth Proportional to 1,080.21, 1,620.78 and 430.77

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Solution

The fourth proportional to 1,080.21, 1,620.78 and 430.77 is: 646.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,080.21 : 1,620.78 = 430.77 : x
  2. Step 2: Convert to fraction form
    1,080.21/1,620.78 = 430.77/x
  3. Step 3: Cross multiply
    1,080.21x = 1,620.78 × 430.77
  4. Step 4: Simplify right side
    1,080.21x = 698,183.40
  5. Step 5: Solve for x
    x = 698,183.40/1,080.21
  6. Step 6: Final answer
    x = 646.34

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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.