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Finding the Fourth Proportional to 238.80, 358.20 and 84.78

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Solution

The fourth proportional to 238.80, 358.20 and 84.78 is: 127.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    238.80 : 358.20 = 84.78 : x
  2. Step 2: Convert to fraction form
    238.80/358.20 = 84.78/x
  3. Step 3: Cross multiply
    238.80x = 358.20 × 84.78
  4. Step 4: Simplify right side
    238.80x = 30,368.20
  5. Step 5: Solve for x
    x = 30,368.20/238.80
  6. Step 6: Final answer
    x = 127.17

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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.