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Finding the Fourth Proportional to 802.55, 1,201.80 and 640.55

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Solution

The fourth proportional to 802.55, 1,201.80 and 640.55 is: 959.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    802.55 : 1,201.80 = 640.55 : x
  2. Step 2: Convert to fraction form
    802.55/1,201.80 = 640.55/x
  3. Step 3: Cross multiply
    802.55x = 1,201.80 × 640.55
  4. Step 4: Simplify right side
    802.55x = 769,812.99
  5. Step 5: Solve for x
    x = 769,812.99/802.55
  6. Step 6: Final answer
    x = 959.21

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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.