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Finding the Fourth Proportional to 399.80, 551.34 and 315.62

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Solution

The fourth proportional to 399.80, 551.34 and 315.62 is: 435.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.80 : 551.34 = 315.62 : x
  2. Step 2: Convert to fraction form
    399.80/551.34 = 315.62/x
  3. Step 3: Cross multiply
    399.80x = 551.34 × 315.62
  4. Step 4: Simplify right side
    399.80x = 174,013.93
  5. Step 5: Solve for x
    x = 174,013.93/399.80
  6. Step 6: Final answer
    x = 435.25

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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.