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Finding the Fourth Proportional to 12,687.40, 19,031.10 and 12,428.20

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Solution

The fourth proportional to 12,687.40, 19,031.10 and 12,428.20 is: 18,642.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    12,687.40 : 19,031.10 = 12,428.20 : x
  2. Step 2: Convert to fraction form
    12,687.40/19,031.10 = 12,428.20/x
  3. Step 3: Cross multiply
    12,687.40x = 19,031.10 × 12,428.20
  4. Step 4: Simplify right side
    12,687.40x = 236,522,317.02
  5. Step 5: Solve for x
    x = 236,522,317.02/12,687.40
  6. Step 6: Final answer
    x = 18,642.30

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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.