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Finding the Fourth Proportional to 662.34, 985.69 and 642.90

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Solution

The fourth proportional to 662.34, 985.69 and 642.90 is: 956.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    662.34 : 985.69 = 642.90 : x
  2. Step 2: Convert to fraction form
    662.34/985.69 = 642.90/x
  3. Step 3: Cross multiply
    662.34x = 985.69 × 642.90
  4. Step 4: Simplify right side
    662.34x = 633,700.10
  5. Step 5: Solve for x
    x = 633,700.10/662.34
  6. Step 6: Final answer
    x = 956.76

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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.