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Finding the Fourth Proportional to 151.58, 209.28 and 99.15

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Solution

The fourth proportional to 151.58, 209.28 and 99.15 is: 136.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    151.58 : 209.28 = 99.15 : x
  2. Step 2: Convert to fraction form
    151.58/209.28 = 99.15/x
  3. Step 3: Cross multiply
    151.58x = 209.28 × 99.15
  4. Step 4: Simplify right side
    151.58x = 20,750.11
  5. Step 5: Solve for x
    x = 20,750.11/151.58
  6. Step 6: Final answer
    x = 136.89

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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.