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Finding the Fourth Proportional to 158.38, 218.55 and 100.15

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Solution

The fourth proportional to 158.38, 218.55 and 100.15 is: 138.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    158.38 : 218.55 = 100.15 : x
  2. Step 2: Convert to fraction form
    158.38/218.55 = 100.15/x
  3. Step 3: Cross multiply
    158.38x = 218.55 × 100.15
  4. Step 4: Simplify right side
    158.38x = 21,887.78
  5. Step 5: Solve for x
    x = 21,887.78/158.38
  6. Step 6: Final answer
    x = 138.20

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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.