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Finding the Fourth Proportional to 27.20, 40.76 and 15.78

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Solution

The fourth proportional to 27.20, 40.76 and 15.78 is: 23.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    27.20 : 40.76 = 15.78 : x
  2. Step 2: Convert to fraction form
    27.20/40.76 = 15.78/x
  3. Step 3: Cross multiply
    27.20x = 40.76 × 15.78
  4. Step 4: Simplify right side
    27.20x = 643.19
  5. Step 5: Solve for x
    x = 643.19/27.20
  6. Step 6: Final answer
    x = 23.65

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.