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Finding the Fourth Proportional to 101.07, 139.78 and 90.13

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Solution

The fourth proportional to 101.07, 139.78 and 90.13 is: 124.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    101.07 : 139.78 = 90.13 : x
  2. Step 2: Convert to fraction form
    101.07/139.78 = 90.13/x
  3. Step 3: Cross multiply
    101.07x = 139.78 × 90.13
  4. Step 4: Simplify right side
    101.07x = 12,598.15
  5. Step 5: Solve for x
    x = 12,598.15/101.07
  6. Step 6: Final answer
    x = 124.65

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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.