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Finding the Fourth Proportional to 72.40, 99.72 and 58.56

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Solution

The fourth proportional to 72.40, 99.72 and 58.56 is: 80.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.40 : 99.72 = 58.56 : x
  2. Step 2: Convert to fraction form
    72.40/99.72 = 58.56/x
  3. Step 3: Cross multiply
    72.40x = 99.72 × 58.56
  4. Step 4: Simplify right side
    72.40x = 5,839.60
  5. Step 5: Solve for x
    x = 5,839.60/72.40
  6. Step 6: Final answer
    x = 80.66

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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.