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Finding the Fourth Proportional to 155.28, 214.28 and 100.15

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Solution

The fourth proportional to 155.28, 214.28 and 100.15 is: 138.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    155.28 : 214.28 = 100.15 : x
  2. Step 2: Convert to fraction form
    155.28/214.28 = 100.15/x
  3. Step 3: Cross multiply
    155.28x = 214.28 × 100.15
  4. Step 4: Simplify right side
    155.28x = 21,460.14
  5. Step 5: Solve for x
    x = 21,460.14/155.28
  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.