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Finding the Fourth Proportional to 1,318.20, 1,819.06 and 728.72

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Solution

The fourth proportional to 1,318.20, 1,819.06 and 728.72 is: 1,005.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,318.20 : 1,819.06 = 728.72 : x
  2. Step 2: Convert to fraction form
    1,318.20/1,819.06 = 728.72/x
  3. Step 3: Cross multiply
    1,318.20x = 1,819.06 × 728.72
  4. Step 4: Simplify right side
    1,318.20x = 1,325,585.40
  5. Step 5: Solve for x
    x = 1,325,585.40/1,318.20
  6. Step 6: Final answer
    x = 1,005.60

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.