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Finding the Fourth Proportional to 827.20, 1,139.51 and 708.78

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Solution

The fourth proportional to 827.20, 1,139.51 and 708.78 is: 976.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    827.20 : 1,139.51 = 708.78 : x
  2. Step 2: Convert to fraction form
    827.20/1,139.51 = 708.78/x
  3. Step 3: Cross multiply
    827.20x = 1,139.51 × 708.78
  4. Step 4: Simplify right side
    827.20x = 807,661.90
  5. Step 5: Solve for x
    x = 807,661.90/827.20
  6. Step 6: Final answer
    x = 976.38

Related Problems

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Double scale
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1.5x scale

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.