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Finding the Fourth Proportional to 711.24, 980.40 and 489.70

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Solution

The fourth proportional to 711.24, 980.40 and 489.70 is: 675.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    711.24 : 980.40 = 489.70 : x
  2. Step 2: Convert to fraction form
    711.24/980.40 = 489.70/x
  3. Step 3: Cross multiply
    711.24x = 980.40 × 489.70
  4. Step 4: Simplify right side
    711.24x = 480,101.88
  5. Step 5: Solve for x
    x = 480,101.88/711.24
  6. Step 6: Final answer
    x = 675.02

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.