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Finding the Fourth Proportional to 438.40, 657.20 and 218.92

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Solution

The fourth proportional to 438.40, 657.20 and 218.92 is: 328.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    438.40 : 657.20 = 218.92 : x
  2. Step 2: Convert to fraction form
    438.40/657.20 = 218.92/x
  3. Step 3: Cross multiply
    438.40x = 657.20 × 218.92
  4. Step 4: Simplify right side
    438.40x = 143,874.22
  5. Step 5: Solve for x
    x = 143,874.22/438.40
  6. Step 6: Final answer
    x = 328.18

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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.