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Finding the Fourth Proportional to 660.28, 911.26 and 398.30

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Solution

The fourth proportional to 660.28, 911.26 and 398.30 is: 549.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.28 : 911.26 = 398.30 : x
  2. Step 2: Convert to fraction form
    660.28/911.26 = 398.30/x
  3. Step 3: Cross multiply
    660.28x = 911.26 × 398.30
  4. Step 4: Simplify right side
    660.28x = 362,954.86
  5. Step 5: Solve for x
    x = 362,954.86/660.28
  6. Step 6: Final answer
    x = 549.70

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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.