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Finding the Fourth Proportional to 438.90, 657.15 and 342.90

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Solution

The fourth proportional to 438.90, 657.15 and 342.90 is: 513.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    438.90 : 657.15 = 342.90 : x
  2. Step 2: Convert to fraction form
    438.90/657.15 = 342.90/x
  3. Step 3: Cross multiply
    438.90x = 657.15 × 342.90
  4. Step 4: Simplify right side
    438.90x = 225,336.74
  5. Step 5: Solve for x
    x = 225,336.74/438.90
  6. Step 6: Final answer
    x = 513.41

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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.