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Finding the Fourth Proportional to 72.52, 99.78 and 62.80

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Solution

The fourth proportional to 72.52, 99.78 and 62.80 is: 86.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.52 : 99.78 = 62.80 : x
  2. Step 2: Convert to fraction form
    72.52/99.78 = 62.80/x
  3. Step 3: Cross multiply
    72.52x = 99.78 × 62.80
  4. Step 4: Simplify right side
    72.52x = 6,266.18
  5. Step 5: Solve for x
    x = 6,266.18/72.52
  6. Step 6: Final answer
    x = 86.41

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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.