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Finding the Fourth Proportional to 721.99, 989.85 and 708.86

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Solution

The fourth proportional to 721.99, 989.85 and 708.86 is: 971.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    721.99 : 989.85 = 708.86 : x
  2. Step 2: Convert to fraction form
    721.99/989.85 = 708.86/x
  3. Step 3: Cross multiply
    721.99x = 989.85 × 708.86
  4. Step 4: Simplify right side
    721.99x = 701,665.07
  5. Step 5: Solve for x
    x = 701,665.07/721.99
  6. Step 6: Final answer
    x = 971.85

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.