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Finding the Fourth Proportional to 421.22, 631.78 and 147.29

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Solution

The fourth proportional to 421.22, 631.78 and 147.29 is: 220.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.22 : 631.78 = 147.29 : x
  2. Step 2: Convert to fraction form
    421.22/631.78 = 147.29/x
  3. Step 3: Cross multiply
    421.22x = 631.78 × 147.29
  4. Step 4: Simplify right side
    421.22x = 93,051.35
  5. Step 5: Solve for x
    x = 93,051.35/421.22
  6. Step 6: Final answer
    x = 220.91

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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.