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Finding the Fourth Proportional to 155.25, 214.14 and 99.90

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Solution

The fourth proportional to 155.25, 214.14 and 99.90 is: 137.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    155.25 : 214.14 = 99.90 : x
  2. Step 2: Convert to fraction form
    155.25/214.14 = 99.90/x
  3. Step 3: Cross multiply
    155.25x = 214.14 × 99.90
  4. Step 4: Simplify right side
    155.25x = 21,392.59
  5. Step 5: Solve for x
    x = 21,392.59/155.25
  6. Step 6: Final answer
    x = 137.79

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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.