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Finding the Fourth Proportional to 665.55, 996.78 and 642.48

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Solution

The fourth proportional to 665.55, 996.78 and 642.48 is: 962.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.55 : 996.78 = 642.48 : x
  2. Step 2: Convert to fraction form
    665.55/996.78 = 642.48/x
  3. Step 3: Cross multiply
    665.55x = 996.78 × 642.48
  4. Step 4: Simplify right side
    665.55x = 640,412.11
  5. Step 5: Solve for x
    x = 640,412.11/665.55
  6. Step 6: Final answer
    x = 962.24

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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.