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Finding the Fourth Proportional to 56.57, 78.07 and 30.70

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Solution

The fourth proportional to 56.57, 78.07 and 30.70 is: 42.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    56.57 : 78.07 = 30.70 : x
  2. Step 2: Convert to fraction form
    56.57/78.07 = 30.70/x
  3. Step 3: Cross multiply
    56.57x = 78.07 × 30.70
  4. Step 4: Simplify right side
    56.57x = 2,396.32
  5. Step 5: Solve for x
    x = 2,396.32/56.57
  6. Step 6: Final answer
    x = 42.36

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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.