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Finding the Fourth Proportional to 675.70, 1,007.78 and 664

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Solution

The fourth proportional to 675.70, 1,007.78 and 664 is: 990.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    675.70 : 1,007.78 = 664 : x
  2. Step 2: Convert to fraction form
    675.70/1,007.78 = 664/x
  3. Step 3: Cross multiply
    675.70x = 1,007.78 × 664
  4. Step 4: Simplify right side
    675.70x = 669,165.92
  5. Step 5: Solve for x
    x = 669,165.92/675.70
  6. Step 6: Final answer
    x = 990.33

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.