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Finding the Fourth Proportional to 821.10, 1,228.56 and 456.15

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Solution

The fourth proportional to 821.10, 1,228.56 and 456.15 is: 682.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    821.10 : 1,228.56 = 456.15 : x
  2. Step 2: Convert to fraction form
    821.10/1,228.56 = 456.15/x
  3. Step 3: Cross multiply
    821.10x = 1,228.56 × 456.15
  4. Step 4: Simplify right side
    821.10x = 560,407.64
  5. Step 5: Solve for x
    x = 560,407.64/821.10
  6. Step 6: Final answer
    x = 682.51

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1.5x scale

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.