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Finding the Fourth Proportional to 1,086.20, 1,498.66 and 643.74

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Solution

The fourth proportional to 1,086.20, 1,498.66 and 643.74 is: 888.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,086.20 : 1,498.66 = 643.74 : x
  2. Step 2: Convert to fraction form
    1,086.20/1,498.66 = 643.74/x
  3. Step 3: Cross multiply
    1,086.20x = 1,498.66 × 643.74
  4. Step 4: Simplify right side
    1,086.20x = 964,747.39
  5. Step 5: Solve for x
    x = 964,747.39/1,086.20
  6. Step 6: Final answer
    x = 888.19

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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.