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Finding the Fourth Proportional to 665.03, 991.86 and 641.81

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Solution

The fourth proportional to 665.03, 991.86 and 641.81 is: 957.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.03 : 991.86 = 641.81 : x
  2. Step 2: Convert to fraction form
    665.03/991.86 = 641.81/x
  3. Step 3: Cross multiply
    665.03x = 991.86 × 641.81
  4. Step 4: Simplify right side
    665.03x = 636,580.71
  5. Step 5: Solve for x
    x = 636,580.71/665.03
  6. Step 6: Final answer
    x = 957.23

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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.