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Finding the Fourth Proportional to 278.78, 416.12 and 258.75

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Solution

The fourth proportional to 278.78, 416.12 and 258.75 is: 386.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    278.78 : 416.12 = 258.75 : x
  2. Step 2: Convert to fraction form
    278.78/416.12 = 258.75/x
  3. Step 3: Cross multiply
    278.78x = 416.12 × 258.75
  4. Step 4: Simplify right side
    278.78x = 107,669.76
  5. Step 5: Solve for x
    x = 107,669.76/278.78
  6. Step 6: Final answer
    x = 386.22

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.