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Finding the Fourth Proportional to 631.45, 947.40 and 220.70

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Solution

The fourth proportional to 631.45, 947.40 and 220.70 is: 331.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    631.45 : 947.40 = 220.70 : x
  2. Step 2: Convert to fraction form
    631.45/947.40 = 220.70/x
  3. Step 3: Cross multiply
    631.45x = 947.40 × 220.70
  4. Step 4: Simplify right side
    631.45x = 209,085.34
  5. Step 5: Solve for x
    x = 209,085.34/631.45
  6. Step 6: Final answer
    x = 331.12

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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.