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Finding the Fourth Proportional to 218.30, 301.28 and 139.66

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Solution

The fourth proportional to 218.30, 301.28 and 139.66 is: 192.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    218.30 : 301.28 = 139.66 : x
  2. Step 2: Convert to fraction form
    218.30/301.28 = 139.66/x
  3. Step 3: Cross multiply
    218.30x = 301.28 × 139.66
  4. Step 4: Simplify right side
    218.30x = 42,076.76
  5. Step 5: Solve for x
    x = 42,076.76/218.30
  6. Step 6: Final answer
    x = 192.75

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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.