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Finding the Fourth Proportional to 775.96, 1,068.06 and 643.48

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Solution

The fourth proportional to 775.96, 1,068.06 and 643.48 is: 885.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    775.96 : 1,068.06 = 643.48 : x
  2. Step 2: Convert to fraction form
    775.96/1,068.06 = 643.48/x
  3. Step 3: Cross multiply
    775.96x = 1,068.06 × 643.48
  4. Step 4: Simplify right side
    775.96x = 687,275.25
  5. Step 5: Solve for x
    x = 687,275.25/775.96
  6. Step 6: Final answer
    x = 885.71

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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.