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Finding the Fourth Proportional to 659.81, 988.26 and 428.00

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Solution

The fourth proportional to 659.81, 988.26 and 428.00 is: 641.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    659.81 : 988.26 = 428.00 : x
  2. Step 2: Convert to fraction form
    659.81/988.26 = 428.00/x
  3. Step 3: Cross multiply
    659.81x = 988.26 × 428.00
  4. Step 4: Simplify right side
    659.81x = 422,968.73
  5. Step 5: Solve for x
    x = 422,968.73/659.81
  6. Step 6: Final answer
    x = 641.04

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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.