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Finding the Fourth Proportional to 764.70, 1,145.70 and 648.60

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Solution

The fourth proportional to 764.70, 1,145.70 and 648.60 is: 971.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    764.70 : 1,145.70 = 648.60 : x
  2. Step 2: Convert to fraction form
    764.70/1,145.70 = 648.60/x
  3. Step 3: Cross multiply
    764.70x = 1,145.70 × 648.60
  4. Step 4: Simplify right side
    764.70x = 743,101.02
  5. Step 5: Solve for x
    x = 743,101.02/764.70
  6. Step 6: Final answer
    x = 971.75

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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.