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Finding the Fourth Proportional to 821.80, 1,223.51 and 821.80

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Solution

The fourth proportional to 821.80, 1,223.51 and 821.80 is: 1,223.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    821.80 : 1,223.51 = 821.80 : x
  2. Step 2: Convert to fraction form
    821.80/1,223.51 = 821.80/x
  3. Step 3: Cross multiply
    821.80x = 1,223.51 × 821.80
  4. Step 4: Simplify right side
    821.80x = 1,005,480.52
  5. Step 5: Solve for x
    x = 1,005,480.52/821.80
  6. Step 6: Final answer
    x = 1,223.51

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.