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Finding the Fourth Proportional to 399.90, 551.38 and 278.32

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Solution

The fourth proportional to 399.90, 551.38 and 278.32 is: 383.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.90 : 551.38 = 278.32 : x
  2. Step 2: Convert to fraction form
    399.90/551.38 = 278.32/x
  3. Step 3: Cross multiply
    399.90x = 551.38 × 278.32
  4. Step 4: Simplify right side
    399.90x = 153,460.08
  5. Step 5: Solve for x
    x = 153,460.08/399.90
  6. Step 6: Final answer
    x = 383.75

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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.