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Finding the Fourth Proportional to 679.34, 1,019.31 and 435.80

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Solution

The fourth proportional to 679.34, 1,019.31 and 435.80 is: 653.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    679.34 : 1,019.31 = 435.80 : x
  2. Step 2: Convert to fraction form
    679.34/1,019.31 = 435.80/x
  3. Step 3: Cross multiply
    679.34x = 1,019.31 × 435.80
  4. Step 4: Simplify right side
    679.34x = 444,215.30
  5. Step 5: Solve for x
    x = 444,215.30/679.34
  6. Step 6: Final answer
    x = 653.89

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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.