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Finding the Fourth Proportional to 821.28, 1,232.80 and 790.16

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Solution

The fourth proportional to 821.28, 1,232.80 and 790.16 is: 1,186.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    821.28 : 1,232.80 = 790.16 : x
  2. Step 2: Convert to fraction form
    821.28/1,232.80 = 790.16/x
  3. Step 3: Cross multiply
    821.28x = 1,232.80 × 790.16
  4. Step 4: Simplify right side
    821.28x = 974,109.25
  5. Step 5: Solve for x
    x = 974,109.25/821.28
  6. Step 6: Final answer
    x = 1,186.09

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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.