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Finding the Fourth Proportional to 1,215.20, 1,819.56 and 939.08

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Solution

The fourth proportional to 1,215.20, 1,819.56 and 939.08 is: 1,406.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,215.20 : 1,819.56 = 939.08 : x
  2. Step 2: Convert to fraction form
    1,215.20/1,819.56 = 939.08/x
  3. Step 3: Cross multiply
    1,215.20x = 1,819.56 × 939.08
  4. Step 4: Simplify right side
    1,215.20x = 1,708,712.40
  5. Step 5: Solve for x
    x = 1,708,712.40/1,215.20
  6. Step 6: Final answer
    x = 1,406.12

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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.