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Finding the Fourth Proportional to 421.90, 632.66 and 129.33

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Solution

The fourth proportional to 421.90, 632.66 and 129.33 is: 193.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.90 : 632.66 = 129.33 : x
  2. Step 2: Convert to fraction form
    421.90/632.66 = 129.33/x
  3. Step 3: Cross multiply
    421.90x = 632.66 × 129.33
  4. Step 4: Simplify right side
    421.90x = 81,821.27
  5. Step 5: Solve for x
    x = 81,821.27/421.90
  6. Step 6: Final answer
    x = 193.93

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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.