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Finding the Fourth Proportional to 60.40, 83.40 and 39.72

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Solution

The fourth proportional to 60.40, 83.40 and 39.72 is: 54.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    60.40 : 83.40 = 39.72 : x
  2. Step 2: Convert to fraction form
    60.40/83.40 = 39.72/x
  3. Step 3: Cross multiply
    60.40x = 83.40 × 39.72
  4. Step 4: Simplify right side
    60.40x = 3,312.65
  5. Step 5: Solve for x
    x = 3,312.65/60.40
  6. Step 6: Final answer
    x = 54.85

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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.