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Finding the Fourth Proportional to 51.80, 77.40 and 42.05

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Solution

The fourth proportional to 51.80, 77.40 and 42.05 is: 62.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    51.80 : 77.40 = 42.05 : x
  2. Step 2: Convert to fraction form
    51.80/77.40 = 42.05/x
  3. Step 3: Cross multiply
    51.80x = 77.40 × 42.05
  4. Step 4: Simplify right side
    51.80x = 3,254.86
  5. Step 5: Solve for x
    x = 3,254.86/51.80
  6. Step 6: Final answer
    x = 62.84

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.