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Finding the Fourth Proportional to 287.86, 397.05 and 278.35

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Solution

The fourth proportional to 287.86, 397.05 and 278.35 is: 383.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.86 : 397.05 = 278.35 : x
  2. Step 2: Convert to fraction form
    287.86/397.05 = 278.35/x
  3. Step 3: Cross multiply
    287.86x = 397.05 × 278.35
  4. Step 4: Simplify right side
    287.86x = 110,518.87
  5. Step 5: Solve for x
    x = 110,518.87/287.86
  6. Step 6: Final answer
    x = 383.93

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.