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Finding the Fourth Proportional to 42.70, 56.40 and 42.70

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Solution

The fourth proportional to 42.70, 56.40 and 42.70 is: 56.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    42.70 : 56.40 = 42.70 : x
  2. Step 2: Convert to fraction form
    42.70/56.40 = 42.70/x
  3. Step 3: Cross multiply
    42.70x = 56.40 × 42.70
  4. Step 4: Simplify right side
    42.70x = 2,408.28
  5. Step 5: Solve for x
    x = 2,408.28/42.70
  6. Step 6: Final answer
    x = 56.40

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Why These Related Problems?

These problems maintain the same ratio (1.32) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.