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Finding the Fourth Proportional to 660.20, 910.79 and 398.07

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Solution

The fourth proportional to 660.20, 910.79 and 398.07 is: 549.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.20 : 910.79 = 398.07 : x
  2. Step 2: Convert to fraction form
    660.20/910.79 = 398.07/x
  3. Step 3: Cross multiply
    660.20x = 910.79 × 398.07
  4. Step 4: Simplify right side
    660.20x = 362,558.18
  5. Step 5: Solve for x
    x = 362,558.18/660.20
  6. Step 6: Final answer
    x = 549.16

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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.