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Finding the Fourth Proportional to 61.42, 84.78 and 40.70

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Solution

The fourth proportional to 61.42, 84.78 and 40.70 is: 56.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    61.42 : 84.78 = 40.70 : x
  2. Step 2: Convert to fraction form
    61.42/84.78 = 40.70/x
  3. Step 3: Cross multiply
    61.42x = 84.78 × 40.70
  4. Step 4: Simplify right side
    61.42x = 3,450.12
  5. Step 5: Solve for x
    x = 3,450.12/61.42
  6. Step 6: Final answer
    x = 56.17

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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.