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Finding the Fourth Proportional to 71.78, 99.06 and 40.70

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Solution

The fourth proportional to 71.78, 99.06 and 40.70 is: 56.17

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.78 : 99.06 = 40.70 : x
  2. Step 2: Convert to fraction form
    71.78/99.06 = 40.70/x
  3. Step 3: Cross multiply
    71.78x = 99.06 × 40.70
  4. Step 4: Simplify right side
    71.78x = 4,031.25
  5. Step 5: Solve for x
    x = 4,031.25/71.78
  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.