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Finding the Fourth Proportional to 665.76, 991.95 and 628.50

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Solution

The fourth proportional to 665.76, 991.95 and 628.50 is: 936.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.76 : 991.95 = 628.50 : x
  2. Step 2: Convert to fraction form
    665.76/991.95 = 628.50/x
  3. Step 3: Cross multiply
    665.76x = 991.95 × 628.50
  4. Step 4: Simplify right side
    665.76x = 623,440.58
  5. Step 5: Solve for x
    x = 623,440.58/665.76
  6. Step 6: Final answer
    x = 936.43

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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.