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Finding the Fourth Proportional to 864.78, 1,297.05 and 279.75

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Solution

The fourth proportional to 864.78, 1,297.05 and 279.75 is: 419.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    864.78 : 1,297.05 = 279.75 : x
  2. Step 2: Convert to fraction form
    864.78/1,297.05 = 279.75/x
  3. Step 3: Cross multiply
    864.78x = 1,297.05 × 279.75
  4. Step 4: Simplify right side
    864.78x = 362,849.74
  5. Step 5: Solve for x
    x = 362,849.74/864.78
  6. Step 6: Final answer
    x = 419.59

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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.