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Finding the Fourth Proportional to 71.79, 99.08 and 42.70

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Solution

The fourth proportional to 71.79, 99.08 and 42.70 is: 58.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.79 : 99.08 = 42.70 : x
  2. Step 2: Convert to fraction form
    71.79/99.08 = 42.70/x
  3. Step 3: Cross multiply
    71.79x = 99.08 × 42.70
  4. Step 4: Simplify right side
    71.79x = 4,230.50
  5. Step 5: Solve for x
    x = 4,230.50/71.79
  6. Step 6: Final answer
    x = 58.93

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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.