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Finding the Fourth Proportional to 801.40, 1,202.10 and 686.20

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Solution

The fourth proportional to 801.40, 1,202.10 and 686.20 is: 1,029.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    801.40 : 1,202.10 = 686.20 : x
  2. Step 2: Convert to fraction form
    801.40/1,202.10 = 686.20/x
  3. Step 3: Cross multiply
    801.40x = 1,202.10 × 686.20
  4. Step 4: Simplify right side
    801.40x = 824,881.02
  5. Step 5: Solve for x
    x = 824,881.02/801.40
  6. Step 6: Final answer
    x = 1,029.30

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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.