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Finding the Fourth Proportional to 726.80, 1,085.38 and 712.40

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Solution

The fourth proportional to 726.80, 1,085.38 and 712.40 is: 1,063.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    726.80 : 1,085.38 = 712.40 : x
  2. Step 2: Convert to fraction form
    726.80/1,085.38 = 712.40/x
  3. Step 3: Cross multiply
    726.80x = 1,085.38 × 712.40
  4. Step 4: Simplify right side
    726.80x = 773,224.71
  5. Step 5: Solve for x
    x = 773,224.71/726.80
  6. Step 6: Final answer
    x = 1,063.88

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.