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Finding the Fourth Proportional to 338.38, 507.40 and 121.90

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Solution

The fourth proportional to 338.38, 507.40 and 121.90 is: 182.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    338.38 : 507.40 = 121.90 : x
  2. Step 2: Convert to fraction form
    338.38/507.40 = 121.90/x
  3. Step 3: Cross multiply
    338.38x = 507.40 × 121.90
  4. Step 4: Simplify right side
    338.38x = 61,852.06
  5. Step 5: Solve for x
    x = 61,852.06/338.38
  6. Step 6: Final answer
    x = 182.79

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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.