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Finding the Fourth Proportional to 769.70, 1,154.28 and 720.50

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Solution

The fourth proportional to 769.70, 1,154.28 and 720.50 is: 1,080.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    769.70 : 1,154.28 = 720.50 : x
  2. Step 2: Convert to fraction form
    769.70/1,154.28 = 720.50/x
  3. Step 3: Cross multiply
    769.70x = 1,154.28 × 720.50
  4. Step 4: Simplify right side
    769.70x = 831,655.67
  5. Step 5: Solve for x
    x = 831,655.67/769.70
  6. Step 6: Final answer
    x = 1,080.49

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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.