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Finding the Fourth Proportional to 857.69, 1,287.06 and 309.83

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Solution

The fourth proportional to 857.69, 1,287.06 and 309.83 is: 464.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    857.69 : 1,287.06 = 309.83 : x
  2. Step 2: Convert to fraction form
    857.69/1,287.06 = 309.83/x
  3. Step 3: Cross multiply
    857.69x = 1,287.06 × 309.83
  4. Step 4: Simplify right side
    857.69x = 398,762.20
  5. Step 5: Solve for x
    x = 398,762.20/857.69
  6. Step 6: Final answer
    x = 464.93

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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.