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Finding the Fourth Proportional to 679.33, 1,020.10 and 420.98

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Solution

The fourth proportional to 679.33, 1,020.10 and 420.98 is: 632.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    679.33 : 1,020.10 = 420.98 : x
  2. Step 2: Convert to fraction form
    679.33/1,020.10 = 420.98/x
  3. Step 3: Cross multiply
    679.33x = 1,020.10 × 420.98
  4. Step 4: Simplify right side
    679.33x = 429,441.70
  5. Step 5: Solve for x
    x = 429,441.70/679.33
  6. Step 6: Final answer
    x = 632.15

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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.