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Finding the Fourth Proportional to 102.79, 154.76 and 90.68

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Solution

The fourth proportional to 102.79, 154.76 and 90.68 is: 136.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    102.79 : 154.76 = 90.68 : x
  2. Step 2: Convert to fraction form
    102.79/154.76 = 90.68/x
  3. Step 3: Cross multiply
    102.79x = 154.76 × 90.68
  4. Step 4: Simplify right side
    102.79x = 14,033.86
  5. Step 5: Solve for x
    x = 14,033.86/102.79
  6. Step 6: Final answer
    x = 136.53

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.