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Finding the Fourth Proportional to 791.65, 1,188 and 278.65

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Solution

The fourth proportional to 791.65, 1,188 and 278.65 is: 418.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    791.65 : 1,188 = 278.65 : x
  2. Step 2: Convert to fraction form
    791.65/1,188 = 278.65/x
  3. Step 3: Cross multiply
    791.65x = 1,188 × 278.65
  4. Step 4: Simplify right side
    791.65x = 331,036.20
  5. Step 5: Solve for x
    x = 331,036.20/791.65
  6. Step 6: Final answer
    x = 418.16

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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.