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Finding the Fourth Proportional to 1,089.78, 1,634.63 and 309.78

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Solution

The fourth proportional to 1,089.78, 1,634.63 and 309.78 is: 464.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,089.78 : 1,634.63 = 309.78 : x
  2. Step 2: Convert to fraction form
    1,089.78/1,634.63 = 309.78/x
  3. Step 3: Cross multiply
    1,089.78x = 1,634.63 × 309.78
  4. Step 4: Simplify right side
    1,089.78x = 506,365.96
  5. Step 5: Solve for x
    x = 506,365.96/1,089.78
  6. Step 6: Final answer
    x = 464.65

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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.