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Finding the Fourth Proportional to 1,105.84, 1,658.22 and 643.78

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Solution

The fourth proportional to 1,105.84, 1,658.22 and 643.78 is: 965.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,105.84 : 1,658.22 = 643.78 : x
  2. Step 2: Convert to fraction form
    1,105.84/1,658.22 = 643.78/x
  3. Step 3: Cross multiply
    1,105.84x = 1,658.22 × 643.78
  4. Step 4: Simplify right side
    1,105.84x = 1,067,519.20
  5. Step 5: Solve for x
    x = 1,067,519.20/1,105.84
  6. Step 6: Final answer
    x = 965.35

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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.