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Finding the Fourth Proportional to 420.27, 626.33 and 398.40

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Solution

The fourth proportional to 420.27, 626.33 and 398.40 is: 593.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.27 : 626.33 = 398.40 : x
  2. Step 2: Convert to fraction form
    420.27/626.33 = 398.40/x
  3. Step 3: Cross multiply
    420.27x = 626.33 × 398.40
  4. Step 4: Simplify right side
    420.27x = 249,526.53
  5. Step 5: Solve for x
    x = 249,526.53/420.27
  6. Step 6: Final answer
    x = 593.73

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.