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Finding the Fourth Proportional to 438.93, 658.40 and 387.09

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Solution

The fourth proportional to 438.93, 658.40 and 387.09 is: 580.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    438.93 : 658.40 = 387.09 : x
  2. Step 2: Convert to fraction form
    438.93/658.40 = 387.09/x
  3. Step 3: Cross multiply
    438.93x = 658.40 × 387.09
  4. Step 4: Simplify right side
    438.93x = 254,858.12
  5. Step 5: Solve for x
    x = 254,858.12/438.93
  6. Step 6: Final answer
    x = 580.64

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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.