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Finding the Fourth Proportional to 51.70, 77.58 and 42.79

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Solution

The fourth proportional to 51.70, 77.58 and 42.79 is: 64.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    51.70 : 77.58 = 42.79 : x
  2. Step 2: Convert to fraction form
    51.70/77.58 = 42.79/x
  3. Step 3: Cross multiply
    51.70x = 77.58 × 42.79
  4. Step 4: Simplify right side
    51.70x = 3,319.05
  5. Step 5: Solve for x
    x = 3,319.05/51.70
  6. Step 6: Final answer
    x = 64.20

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.