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Finding the Fourth Proportional to 289.68, 400.08 and 278.88

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Solution

The fourth proportional to 289.68, 400.08 and 278.88 is: 385.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    289.68 : 400.08 = 278.88 : x
  2. Step 2: Convert to fraction form
    289.68/400.08 = 278.88/x
  3. Step 3: Cross multiply
    289.68x = 400.08 × 278.88
  4. Step 4: Simplify right side
    289.68x = 111,574.31
  5. Step 5: Solve for x
    x = 111,574.31/289.68
  6. Step 6: Final answer
    x = 385.16

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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.