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Finding the Fourth Proportional to 981.20, 1,350.18 and 905.72

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Solution

The fourth proportional to 981.20, 1,350.18 and 905.72 is: 1,246.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    981.20 : 1,350.18 = 905.72 : x
  2. Step 2: Convert to fraction form
    981.20/1,350.18 = 905.72/x
  3. Step 3: Cross multiply
    981.20x = 1,350.18 × 905.72
  4. Step 4: Simplify right side
    981.20x = 1,222,885.03
  5. Step 5: Solve for x
    x = 1,222,885.03/981.20
  6. Step 6: Final answer
    x = 1,246.32

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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.