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Finding the Fourth Proportional to 99.09, 148.49 and 87.21

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Solution

The fourth proportional to 99.09, 148.49 and 87.21 is: 130.69

Step by Step Solution

  1. Step 1: Write the proportion equation
    99.09 : 148.49 = 87.21 : x
  2. Step 2: Convert to fraction form
    99.09/148.49 = 87.21/x
  3. Step 3: Cross multiply
    99.09x = 148.49 × 87.21
  4. Step 4: Simplify right side
    99.09x = 12,949.29
  5. Step 5: Solve for x
    x = 12,949.29/99.09
  6. Step 6: Final answer
    x = 130.69

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.