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Finding the Fourth Proportional to 880.81, 1,321.36 and 393.90

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Solution

The fourth proportional to 880.81, 1,321.36 and 393.90 is: 590.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    880.81 : 1,321.36 = 393.90 : x
  2. Step 2: Convert to fraction form
    880.81/1,321.36 = 393.90/x
  3. Step 3: Cross multiply
    880.81x = 1,321.36 × 393.90
  4. Step 4: Simplify right side
    880.81x = 520,479.98
  5. Step 5: Solve for x
    x = 520,479.98/880.81
  6. Step 6: Final answer
    x = 590.91

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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.