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Finding the Fourth Proportional to 838.18, 1,256.55 and 405.10

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Solution

The fourth proportional to 838.18, 1,256.55 and 405.10 is: 607.30

Step by Step Solution

  1. Step 1: Write the proportion equation
    838.18 : 1,256.55 = 405.10 : x
  2. Step 2: Convert to fraction form
    838.18/1,256.55 = 405.10/x
  3. Step 3: Cross multiply
    838.18x = 1,256.55 × 405.10
  4. Step 4: Simplify right side
    838.18x = 509,028.41
  5. Step 5: Solve for x
    x = 509,028.41/838.18
  6. Step 6: Final answer
    x = 607.30

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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.