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Finding the Fourth Proportional to 756.66, 1,043.56 and 638.90

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Solution

The fourth proportional to 756.66, 1,043.56 and 638.90 is: 881.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    756.66 : 1,043.56 = 638.90 : x
  2. Step 2: Convert to fraction form
    756.66/1,043.56 = 638.90/x
  3. Step 3: Cross multiply
    756.66x = 1,043.56 × 638.90
  4. Step 4: Simplify right side
    756.66x = 666,731.50
  5. Step 5: Solve for x
    x = 666,731.50/756.66
  6. Step 6: Final answer
    x = 881.16

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.