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Finding the Fourth Proportional to 781.90, 1,172.45 and 288.28

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Solution

The fourth proportional to 781.90, 1,172.45 and 288.28 is: 432.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.90 : 1,172.45 = 288.28 : x
  2. Step 2: Convert to fraction form
    781.90/1,172.45 = 288.28/x
  3. Step 3: Cross multiply
    781.90x = 1,172.45 × 288.28
  4. Step 4: Simplify right side
    781.90x = 337,993.89
  5. Step 5: Solve for x
    x = 337,993.89/781.90
  6. Step 6: Final answer
    x = 432.27

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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.