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Finding the Fourth Proportional to 55.40, 76.45 and 30.83

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Solution

The fourth proportional to 55.40, 76.45 and 30.83 is: 42.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    55.40 : 76.45 = 30.83 : x
  2. Step 2: Convert to fraction form
    55.40/76.45 = 30.83/x
  3. Step 3: Cross multiply
    55.40x = 76.45 × 30.83
  4. Step 4: Simplify right side
    55.40x = 2,357.07
  5. Step 5: Solve for x
    x = 2,357.07/55.40
  6. Step 6: Final answer
    x = 42.55

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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.