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Finding the Fourth Proportional to 725.65, 1,089.65 and 653.15

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Solution

The fourth proportional to 725.65, 1,089.65 and 653.15 is: 980.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    725.65 : 1,089.65 = 653.15 : x
  2. Step 2: Convert to fraction form
    725.65/1,089.65 = 653.15/x
  3. Step 3: Cross multiply
    725.65x = 1,089.65 × 653.15
  4. Step 4: Simplify right side
    725.65x = 711,709.25
  5. Step 5: Solve for x
    x = 711,709.25/725.65
  6. Step 6: Final answer
    x = 980.79

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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.