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Finding the Fourth Proportional to 2,719.20, 4,079.34 and 987.78

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Solution

The fourth proportional to 2,719.20, 4,079.34 and 987.78 is: 1,481.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    2,719.20 : 4,079.34 = 987.78 : x
  2. Step 2: Convert to fraction form
    2,719.20/4,079.34 = 987.78/x
  3. Step 3: Cross multiply
    2,719.20x = 4,079.34 × 987.78
  4. Step 4: Simplify right side
    2,719.20x = 4,029,490.47
  5. Step 5: Solve for x
    x = 4,029,490.47/2,719.20
  6. Step 6: Final answer
    x = 1,481.87

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1.5x scale

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.