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Finding the Fourth Proportional to 801.44, 1,202.40 and 390.80

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Solution

The fourth proportional to 801.44, 1,202.40 and 390.80 is: 586.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    801.44 : 1,202.40 = 390.80 : x
  2. Step 2: Convert to fraction form
    801.44/1,202.40 = 390.80/x
  3. Step 3: Cross multiply
    801.44x = 1,202.40 × 390.80
  4. Step 4: Simplify right side
    801.44x = 469,897.92
  5. Step 5: Solve for x
    x = 469,897.92/801.44
  6. Step 6: Final answer
    x = 586.32

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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.