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Finding the Fourth Proportional to 40.65, 56.08 and 28.20

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Solution

The fourth proportional to 40.65, 56.08 and 28.20 is: 38.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    40.65 : 56.08 = 28.20 : x
  2. Step 2: Convert to fraction form
    40.65/56.08 = 28.20/x
  3. Step 3: Cross multiply
    40.65x = 56.08 × 28.20
  4. Step 4: Simplify right side
    40.65x = 1,581.46
  5. Step 5: Solve for x
    x = 1,581.46/40.65
  6. Step 6: Final answer
    x = 38.90

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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.