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Finding the Fourth Proportional to 100.07, 138.05 and 65.11

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Solution

The fourth proportional to 100.07, 138.05 and 65.11 is: 89.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    100.07 : 138.05 = 65.11 : x
  2. Step 2: Convert to fraction form
    100.07/138.05 = 65.11/x
  3. Step 3: Cross multiply
    100.07x = 138.05 × 65.11
  4. Step 4: Simplify right side
    100.07x = 8,987.42
  5. Step 5: Solve for x
    x = 8,987.42/100.07
  6. Step 6: Final answer
    x = 89.82

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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.