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Finding the Fourth Proportional to 380.90, 571.34 and 137.40

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Solution

The fourth proportional to 380.90, 571.34 and 137.40 is: 206.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    380.90 : 571.34 = 137.40 : x
  2. Step 2: Convert to fraction form
    380.90/571.34 = 137.40/x
  3. Step 3: Cross multiply
    380.90x = 571.34 × 137.40
  4. Step 4: Simplify right side
    380.90x = 78,501.43
  5. Step 5: Solve for x
    x = 78,501.43/380.90
  6. Step 6: Final answer
    x = 206.10

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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.