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Finding the Fourth Proportional to 663.93, 990.23 and 643.95

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Solution

The fourth proportional to 663.93, 990.23 and 643.95 is: 960.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    663.93 : 990.23 = 643.95 : x
  2. Step 2: Convert to fraction form
    663.93/990.23 = 643.95/x
  3. Step 3: Cross multiply
    663.93x = 990.23 × 643.95
  4. Step 4: Simplify right side
    663.93x = 637,655.39
  5. Step 5: Solve for x
    x = 637,655.39/663.93
  6. Step 6: Final answer
    x = 960.43

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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.