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Finding the Fourth Proportional to 72.26, 99.81 and 57.78

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Solution

The fourth proportional to 72.26, 99.81 and 57.78 is: 79.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.26 : 99.81 = 57.78 : x
  2. Step 2: Convert to fraction form
    72.26/99.81 = 57.78/x
  3. Step 3: Cross multiply
    72.26x = 99.81 × 57.78
  4. Step 4: Simplify right side
    72.26x = 5,767.02
  5. Step 5: Solve for x
    x = 5,767.02/72.26
  6. Step 6: Final answer
    x = 79.81

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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.