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Finding the Fourth Proportional to 828.30, 1,242.45 and 768.90

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Solution

The fourth proportional to 828.30, 1,242.45 and 768.90 is: 1,153.35

Step by Step Solution

  1. Step 1: Write the proportion equation
    828.30 : 1,242.45 = 768.90 : x
  2. Step 2: Convert to fraction form
    828.30/1,242.45 = 768.90/x
  3. Step 3: Cross multiply
    828.30x = 1,242.45 × 768.90
  4. Step 4: Simplify right side
    828.30x = 955,319.81
  5. Step 5: Solve for x
    x = 955,319.81/828.30
  6. Step 6: Final answer
    x = 1,153.35

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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.