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Finding the Fourth Proportional to 154.90, 213.72 and 99.63

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Solution

The fourth proportional to 154.90, 213.72 and 99.63 is: 137.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    154.90 : 213.72 = 99.63 : x
  2. Step 2: Convert to fraction form
    154.90/213.72 = 99.63/x
  3. Step 3: Cross multiply
    154.90x = 213.72 × 99.63
  4. Step 4: Simplify right side
    154.90x = 21,293.11
  5. Step 5: Solve for x
    x = 21,293.11/154.90
  6. Step 6: Final answer
    x = 137.47

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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.