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Finding the Fourth Proportional to 764.90, 1,147.35 and 688.10

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Solution

The fourth proportional to 764.90, 1,147.35 and 688.10 is: 1,032.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    764.90 : 1,147.35 = 688.10 : x
  2. Step 2: Convert to fraction form
    764.90/1,147.35 = 688.10/x
  3. Step 3: Cross multiply
    764.90x = 1,147.35 × 688.10
  4. Step 4: Simplify right side
    764.90x = 789,491.54
  5. Step 5: Solve for x
    x = 789,491.54/764.90
  6. Step 6: Final answer
    x = 1,032.15

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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.