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Finding the Fourth Proportional to 660.42, 911.43 and 398.34

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Solution

The fourth proportional to 660.42, 911.43 and 398.34 is: 549.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    660.42 : 911.43 = 398.34 : x
  2. Step 2: Convert to fraction form
    660.42/911.43 = 398.34/x
  3. Step 3: Cross multiply
    660.42x = 911.43 × 398.34
  4. Step 4: Simplify right side
    660.42x = 363,059.03
  5. Step 5: Solve for x
    x = 363,059.03/660.42
  6. Step 6: Final answer
    x = 549.74

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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.