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Finding the Fourth Proportional to 55.29, 76.30 and 30.72

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Solution

The fourth proportional to 55.29, 76.30 and 30.72 is: 42.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    55.29 : 76.30 = 30.72 : x
  2. Step 2: Convert to fraction form
    55.29/76.30 = 30.72/x
  3. Step 3: Cross multiply
    55.29x = 76.30 × 30.72
  4. Step 4: Simplify right side
    55.29x = 2,343.78
  5. Step 5: Solve for x
    x = 2,343.78/55.29
  6. Step 6: Final answer
    x = 42.39

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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.