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Finding the Fourth Proportional to 380.21, 570.35 and 136.74

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Solution

The fourth proportional to 380.21, 570.35 and 136.74 is: 205.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    380.21 : 570.35 = 136.74 : x
  2. Step 2: Convert to fraction form
    380.21/570.35 = 136.74/x
  3. Step 3: Cross multiply
    380.21x = 570.35 × 136.74
  4. Step 4: Simplify right side
    380.21x = 77,989.66
  5. Step 5: Solve for x
    x = 77,989.66/380.21
  6. Step 6: Final answer
    x = 205.12

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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.