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Finding the Fourth Proportional to 717.40, 989.38 and 569.78

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Solution

The fourth proportional to 717.40, 989.38 and 569.78 is: 785.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    717.40 : 989.38 = 569.78 : x
  2. Step 2: Convert to fraction form
    717.40/989.38 = 569.78/x
  3. Step 3: Cross multiply
    717.40x = 989.38 × 569.78
  4. Step 4: Simplify right side
    717.40x = 563,728.94
  5. Step 5: Solve for x
    x = 563,728.94/717.40
  6. Step 6: Final answer
    x = 785.79

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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.