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Finding the Fourth Proportional to 100.85, 150.93 and 85.66

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Solution

The fourth proportional to 100.85, 150.93 and 85.66 is: 128.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    100.85 : 150.93 = 85.66 : x
  2. Step 2: Convert to fraction form
    100.85/150.93 = 85.66/x
  3. Step 3: Cross multiply
    100.85x = 150.93 × 85.66
  4. Step 4: Simplify right side
    100.85x = 12,928.29
  5. Step 5: Solve for x
    x = 12,928.29/100.85
  6. Step 6: Final answer
    x = 128.20

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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.