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Finding the Fourth Proportional to 659.14, 987.80 and 639.43

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Solution

The fourth proportional to 659.14, 987.80 and 639.43 is: 958.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.14 : 987.80 = 639.43 : x
  2. Step 2: Convert to fraction form
    659.14/987.80 = 639.43/x
  3. Step 3: Cross multiply
    659.14x = 987.80 × 639.43
  4. Step 4: Simplify right side
    659.14x = 631,623.29
  5. Step 5: Solve for x
    x = 631,623.29/659.14
  6. Step 6: Final answer
    x = 958.26

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.