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Finding the Fourth Proportional to 287.94, 397.15 and 278.42

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Solution

The fourth proportional to 287.94, 397.15 and 278.42 is: 384.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.94 : 397.15 = 278.42 : x
  2. Step 2: Convert to fraction form
    287.94/397.15 = 278.42/x
  3. Step 3: Cross multiply
    287.94x = 397.15 × 278.42
  4. Step 4: Simplify right side
    287.94x = 110,574.50
  5. Step 5: Solve for x
    x = 110,574.50/287.94
  6. Step 6: Final answer
    x = 384.02

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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.