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Finding the Fourth Proportional to 781.82, 1,080.07 and 663.59

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Solution

The fourth proportional to 781.82, 1,080.07 and 663.59 is: 916.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.82 : 1,080.07 = 663.59 : x
  2. Step 2: Convert to fraction form
    781.82/1,080.07 = 663.59/x
  3. Step 3: Cross multiply
    781.82x = 1,080.07 × 663.59
  4. Step 4: Simplify right side
    781.82x = 716,724.69
  5. Step 5: Solve for x
    x = 716,724.69/781.82
  6. Step 6: Final answer
    x = 916.74

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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.