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Finding the Fourth Proportional to 339.80, 509.70 and 217.76

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Solution

The fourth proportional to 339.80, 509.70 and 217.76 is: 326.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    339.80 : 509.70 = 217.76 : x
  2. Step 2: Convert to fraction form
    339.80/509.70 = 217.76/x
  3. Step 3: Cross multiply
    339.80x = 509.70 × 217.76
  4. Step 4: Simplify right side
    339.80x = 110,992.27
  5. Step 5: Solve for x
    x = 110,992.27/339.80
  6. Step 6: Final answer
    x = 326.64

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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.