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Finding the Fourth Proportional to 804.64, 1,206.90 and 256.78

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Solution

The fourth proportional to 804.64, 1,206.90 and 256.78 is: 385.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    804.64 : 1,206.90 = 256.78 : x
  2. Step 2: Convert to fraction form
    804.64/1,206.90 = 256.78/x
  3. Step 3: Cross multiply
    804.64x = 1,206.90 × 256.78
  4. Step 4: Simplify right side
    804.64x = 309,907.78
  5. Step 5: Solve for x
    x = 309,907.78/804.64
  6. Step 6: Final answer
    x = 385.15

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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.