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Finding the Fourth Proportional to 421.14, 631.28 and 147.05

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Solution

The fourth proportional to 421.14, 631.28 and 147.05 is: 220.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.14 : 631.28 = 147.05 : x
  2. Step 2: Convert to fraction form
    421.14/631.28 = 147.05/x
  3. Step 3: Cross multiply
    421.14x = 631.28 × 147.05
  4. Step 4: Simplify right side
    421.14x = 92,829.30
  5. Step 5: Solve for x
    x = 92,829.30/421.14
  6. Step 6: Final answer
    x = 220.42

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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.