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Finding the Fourth Proportional to 102.16, 153.38 and 85.15

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Solution

The fourth proportional to 102.16, 153.38 and 85.15 is: 127.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    102.16 : 153.38 = 85.15 : x
  2. Step 2: Convert to fraction form
    102.16/153.38 = 85.15/x
  3. Step 3: Cross multiply
    102.16x = 153.38 × 85.15
  4. Step 4: Simplify right side
    102.16x = 13,060.31
  5. Step 5: Solve for x
    x = 13,060.31/102.16
  6. Step 6: Final answer
    x = 127.84

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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.