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Finding the Fourth Proportional to 102.20, 141.08 and 65.42

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Solution

The fourth proportional to 102.20, 141.08 and 65.42 is: 90.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    102.20 : 141.08 = 65.42 : x
  2. Step 2: Convert to fraction form
    102.20/141.08 = 65.42/x
  3. Step 3: Cross multiply
    102.20x = 141.08 × 65.42
  4. Step 4: Simplify right side
    102.20x = 9,228.42
  5. Step 5: Solve for x
    x = 9,228.42/102.20
  6. Step 6: Final answer
    x = 90.30

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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.