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Finding the Fourth Proportional to 1,105.92, 1,658.28 and 643.80

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Solution

The fourth proportional to 1,105.92, 1,658.28 and 643.80 is: 965.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,105.92 : 1,658.28 = 643.80 : x
  2. Step 2: Convert to fraction form
    1,105.92/1,658.28 = 643.80/x
  3. Step 3: Cross multiply
    1,105.92x = 1,658.28 × 643.80
  4. Step 4: Simplify right side
    1,105.92x = 1,067,600.66
  5. Step 5: Solve for x
    x = 1,067,600.66/1,105.92
  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.