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Finding the Fourth Proportional to 99.86, 138.51 and 99.05

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Solution

The fourth proportional to 99.86, 138.51 and 99.05 is: 137.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    99.86 : 138.51 = 99.05 : x
  2. Step 2: Convert to fraction form
    99.86/138.51 = 99.05/x
  3. Step 3: Cross multiply
    99.86x = 138.51 × 99.05
  4. Step 4: Simplify right side
    99.86x = 13,718.72
  5. Step 5: Solve for x
    x = 13,718.72/99.86
  6. Step 6: Final answer
    x = 137.39

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.