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Finding the Fourth Proportional to 660.75, 911.87 and 428.28

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Solution

The fourth proportional to 660.75, 911.87 and 428.28 is: 591.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.75 : 911.87 = 428.28 : x
  2. Step 2: Convert to fraction form
    660.75/911.87 = 428.28/x
  3. Step 3: Cross multiply
    660.75x = 911.87 × 428.28
  4. Step 4: Simplify right side
    660.75x = 390,533.54
  5. Step 5: Solve for x
    x = 390,533.54/660.75
  6. Step 6: Final answer
    x = 591.05

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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.