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Finding the Fourth Proportional to 631.69, 947.60 and 220.78

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Solution

The fourth proportional to 631.69, 947.60 and 220.78 is: 331.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    631.69 : 947.60 = 220.78 : x
  2. Step 2: Convert to fraction form
    631.69/947.60 = 220.78/x
  3. Step 3: Cross multiply
    631.69x = 947.60 × 220.78
  4. Step 4: Simplify right side
    631.69x = 209,211.13
  5. Step 5: Solve for x
    x = 209,211.13/631.69
  6. Step 6: Final answer
    x = 331.19

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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.