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Finding the Fourth Proportional to 218.36, 301.28 and 139.72

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Solution

The fourth proportional to 218.36, 301.28 and 139.72 is: 192.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    218.36 : 301.28 = 139.72 : x
  2. Step 2: Convert to fraction form
    218.36/301.28 = 139.72/x
  3. Step 3: Cross multiply
    218.36x = 301.28 × 139.72
  4. Step 4: Simplify right side
    218.36x = 42,094.84
  5. Step 5: Solve for x
    x = 42,094.84/218.36
  6. Step 6: Final answer
    x = 192.78

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.