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Finding the Fourth Proportional to 15.69, 23.40 and 13.78

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Solution

The fourth proportional to 15.69, 23.40 and 13.78 is: 20.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    15.69 : 23.40 = 13.78 : x
  2. Step 2: Convert to fraction form
    15.69/23.40 = 13.78/x
  3. Step 3: Cross multiply
    15.69x = 23.40 × 13.78
  4. Step 4: Simplify right side
    15.69x = 322.45
  5. Step 5: Solve for x
    x = 322.45/15.69
  6. Step 6: Final answer
    x = 20.55

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.