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Finding the Fourth Proportional to 421.68, 632.70 and 147.81

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Solution

The fourth proportional to 421.68, 632.70 and 147.81 is: 221.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.68 : 632.70 = 147.81 : x
  2. Step 2: Convert to fraction form
    421.68/632.70 = 147.81/x
  3. Step 3: Cross multiply
    421.68x = 632.70 × 147.81
  4. Step 4: Simplify right side
    421.68x = 93,519.39
  5. Step 5: Solve for x
    x = 93,519.39/421.68
  6. Step 6: Final answer
    x = 221.78

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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.