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Finding the Fourth Proportional to 421.72, 632.78 and 291.92

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Solution

The fourth proportional to 421.72, 632.78 and 291.92 is: 438.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.72 : 632.78 = 291.92 : x
  2. Step 2: Convert to fraction form
    421.72/632.78 = 291.92/x
  3. Step 3: Cross multiply
    421.72x = 632.78 × 291.92
  4. Step 4: Simplify right side
    421.72x = 184,721.14
  5. Step 5: Solve for x
    x = 184,721.14/421.72
  6. Step 6: Final answer
    x = 438.02

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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.