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Finding the Fourth Proportional to 791.36, 1,187.36 and 278.40

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Solution

The fourth proportional to 791.36, 1,187.36 and 278.40 is: 417.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    791.36 : 1,187.36 = 278.40 : x
  2. Step 2: Convert to fraction form
    791.36/1,187.36 = 278.40/x
  3. Step 3: Cross multiply
    791.36x = 1,187.36 × 278.40
  4. Step 4: Simplify right side
    791.36x = 330,561.02
  5. Step 5: Solve for x
    x = 330,561.02/791.36
  6. Step 6: Final answer
    x = 417.71

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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.