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Finding the Fourth Proportional to 663.21, 989.93 and 577.15

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Solution

The fourth proportional to 663.21, 989.93 and 577.15 is: 861.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    663.21 : 989.93 = 577.15 : x
  2. Step 2: Convert to fraction form
    663.21/989.93 = 577.15/x
  3. Step 3: Cross multiply
    663.21x = 989.93 × 577.15
  4. Step 4: Simplify right side
    663.21x = 571,337.07
  5. Step 5: Solve for x
    x = 571,337.07/663.21
  6. Step 6: Final answer
    x = 861.47

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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.