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Finding the Fourth Proportional to 1,078.28, 1,616.87 and 428.66

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Solution

The fourth proportional to 1,078.28, 1,616.87 and 428.66 is: 642.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,078.28 : 1,616.87 = 428.66 : x
  2. Step 2: Convert to fraction form
    1,078.28/1,616.87 = 428.66/x
  3. Step 3: Cross multiply
    1,078.28x = 1,616.87 × 428.66
  4. Step 4: Simplify right side
    1,078.28x = 693,080.48
  5. Step 5: Solve for x
    x = 693,080.48/1,078.28
  6. Step 6: Final answer
    x = 642.77

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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.