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Finding the Fourth Proportional to 12.95, 19.40 and 7.88

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Solution

The fourth proportional to 12.95, 19.40 and 7.88 is: 11.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    12.95 : 19.40 = 7.88 : x
  2. Step 2: Convert to fraction form
    12.95/19.40 = 7.88/x
  3. Step 3: Cross multiply
    12.95x = 19.40 × 7.88
  4. Step 4: Simplify right side
    12.95x = 152.74
  5. Step 5: Solve for x
    x = 152.74/12.95
  6. Step 6: Final answer
    x = 11.80

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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.