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Finding the Fourth Proportional to 338.80, 508.20 and 317.20

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Solution

The fourth proportional to 338.80, 508.20 and 317.20 is: 475.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    338.80 : 508.20 = 317.20 : x
  2. Step 2: Convert to fraction form
    338.80/508.20 = 317.20/x
  3. Step 3: Cross multiply
    338.80x = 508.20 × 317.20
  4. Step 4: Simplify right side
    338.80x = 161,201.04
  5. Step 5: Solve for x
    x = 161,201.04/338.80
  6. Step 6: Final answer
    x = 475.80

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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.