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Finding the Fourth Proportional to 56.40, 77.79 and 38.93

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Solution

The fourth proportional to 56.40, 77.79 and 38.93 is: 53.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    56.40 : 77.79 = 38.93 : x
  2. Step 2: Convert to fraction form
    56.40/77.79 = 38.93/x
  3. Step 3: Cross multiply
    56.40x = 77.79 × 38.93
  4. Step 4: Simplify right side
    56.40x = 3,028.56
  5. Step 5: Solve for x
    x = 3,028.56/56.40
  6. Step 6: Final answer
    x = 53.70

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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.