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Finding the Fourth Proportional to 981.80, 1,355.44 and 668.76

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Solution

The fourth proportional to 981.80, 1,355.44 and 668.76 is: 923.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    981.80 : 1,355.44 = 668.76 : x
  2. Step 2: Convert to fraction form
    981.80/1,355.44 = 668.76/x
  3. Step 3: Cross multiply
    981.80x = 1,355.44 × 668.76
  4. Step 4: Simplify right side
    981.80x = 906,464.05
  5. Step 5: Solve for x
    x = 906,464.05/981.80
  6. Step 6: Final answer
    x = 923.27

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Double scale
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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.