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Finding the Fourth Proportional to 399.95, 551.85 and 306.80

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Solution

The fourth proportional to 399.95, 551.85 and 306.80 is: 423.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    399.95 : 551.85 = 306.80 : x
  2. Step 2: Convert to fraction form
    399.95/551.85 = 306.80/x
  3. Step 3: Cross multiply
    399.95x = 551.85 × 306.80
  4. Step 4: Simplify right side
    399.95x = 169,307.58
  5. Step 5: Solve for x
    x = 169,307.58/399.95
  6. Step 6: Final answer
    x = 423.32

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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.