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Finding the Fourth Proportional to 421.40, 632.15 and 157.81

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Solution

The fourth proportional to 421.40, 632.15 and 157.81 is: 236.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.40 : 632.15 = 157.81 : x
  2. Step 2: Convert to fraction form
    421.40/632.15 = 157.81/x
  3. Step 3: Cross multiply
    421.40x = 632.15 × 157.81
  4. Step 4: Simplify right side
    421.40x = 99,759.59
  5. Step 5: Solve for x
    x = 99,759.59/421.40
  6. Step 6: Final answer
    x = 236.73

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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.