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Finding the Fourth Proportional to 801.19, 1,200.77 and 390.45

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Solution

The fourth proportional to 801.19, 1,200.77 and 390.45 is: 585.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    801.19 : 1,200.77 = 390.45 : x
  2. Step 2: Convert to fraction form
    801.19/1,200.77 = 390.45/x
  3. Step 3: Cross multiply
    801.19x = 1,200.77 × 390.45
  4. Step 4: Simplify right side
    801.19x = 468,838.69
  5. Step 5: Solve for x
    x = 468,838.69/801.19
  6. Step 6: Final answer
    x = 585.18

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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.