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Finding the Fourth Proportional to 639, 958.55 and 216.86

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Solution

The fourth proportional to 639, 958.55 and 216.86 is: 325.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    639 : 958.55 = 216.86 : x
  2. Step 2: Convert to fraction form
    639/958.55 = 216.86/x
  3. Step 3: Cross multiply
    639x = 958.55 × 216.86
  4. Step 4: Simplify right side
    639x = 207,865.28
  5. Step 5: Solve for x
    x = 207,865.28/639
  6. Step 6: Final answer
    x = 325.30

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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.