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Finding the Fourth Proportional to 726.42, 1,089.81 and 645.87

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Solution

The fourth proportional to 726.42, 1,089.81 and 645.87 is: 968.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    726.42 : 1,089.81 = 645.87 : x
  2. Step 2: Convert to fraction form
    726.42/1,089.81 = 645.87/x
  3. Step 3: Cross multiply
    726.42x = 1,089.81 × 645.87
  4. Step 4: Simplify right side
    726.42x = 703,875.58
  5. Step 5: Solve for x
    x = 703,875.58/726.42
  6. Step 6: Final answer
    x = 968.97

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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.