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Finding the Fourth Proportional to 938.79, 1,408.64 and 419.54

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Solution

The fourth proportional to 938.79, 1,408.64 and 419.54 is: 629.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    938.79 : 1,408.64 = 419.54 : x
  2. Step 2: Convert to fraction form
    938.79/1,408.64 = 419.54/x
  3. Step 3: Cross multiply
    938.79x = 1,408.64 × 419.54
  4. Step 4: Simplify right side
    938.79x = 590,971.68
  5. Step 5: Solve for x
    x = 590,971.68/938.79
  6. Step 6: Final answer
    x = 629.50

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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.