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Finding the Fourth Proportional to 421.23, 631.90 and 147.39

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Solution

The fourth proportional to 421.23, 631.90 and 147.39 is: 221.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.23 : 631.90 = 147.39 : x
  2. Step 2: Convert to fraction form
    421.23/631.90 = 147.39/x
  3. Step 3: Cross multiply
    421.23x = 631.90 × 147.39
  4. Step 4: Simplify right side
    421.23x = 93,133.56
  5. Step 5: Solve for x
    x = 93,133.56/421.23
  6. Step 6: Final answer
    x = 221.10

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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.