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Finding the Fourth Proportional to 801.78, 1,106.21 and 470.21

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Solution

The fourth proportional to 801.78, 1,106.21 and 470.21 is: 648.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    801.78 : 1,106.21 = 470.21 : x
  2. Step 2: Convert to fraction form
    801.78/1,106.21 = 470.21/x
  3. Step 3: Cross multiply
    801.78x = 1,106.21 × 470.21
  4. Step 4: Simplify right side
    801.78x = 520,143.12
  5. Step 5: Solve for x
    x = 520,143.12/801.78
  6. Step 6: Final answer
    x = 648.74

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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.