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Finding the Fourth Proportional to 2,658.12, 3,987.78 and 809.40

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Solution

The fourth proportional to 2,658.12, 3,987.78 and 809.40 is: 1,214.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    2,658.12 : 3,987.78 = 809.40 : x
  2. Step 2: Convert to fraction form
    2,658.12/3,987.78 = 809.40/x
  3. Step 3: Cross multiply
    2,658.12x = 3,987.78 × 809.40
  4. Step 4: Simplify right side
    2,658.12x = 3,227,709.13
  5. Step 5: Solve for x
    x = 3,227,709.13/2,658.12
  6. Step 6: Final answer
    x = 1,214.28

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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.