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Finding the Fourth Proportional to 619.45, 931.20 and 438.10

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Solution

The fourth proportional to 619.45, 931.20 and 438.10 is: 658.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    619.45 : 931.20 = 438.10 : x
  2. Step 2: Convert to fraction form
    619.45/931.20 = 438.10/x
  3. Step 3: Cross multiply
    619.45x = 931.20 × 438.10
  4. Step 4: Simplify right side
    619.45x = 407,958.72
  5. Step 5: Solve for x
    x = 407,958.72/619.45
  6. Step 6: Final answer
    x = 658.58

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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.