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Finding the Fourth Proportional to 838.56, 1,256.64 and 405.12

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Solution

The fourth proportional to 838.56, 1,256.64 and 405.12 is: 607.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    838.56 : 1,256.64 = 405.12 : x
  2. Step 2: Convert to fraction form
    838.56/1,256.64 = 405.12/x
  3. Step 3: Cross multiply
    838.56x = 1,256.64 × 405.12
  4. Step 4: Simplify right side
    838.56x = 509,090.00
  5. Step 5: Solve for x
    x = 509,090.00/838.56
  6. Step 6: Final answer
    x = 607.10

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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.