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Finding the Fourth Proportional to 454.79, 678.88 and 420.95

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Solution

The fourth proportional to 454.79, 678.88 and 420.95 is: 628.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    454.79 : 678.88 = 420.95 : x
  2. Step 2: Convert to fraction form
    454.79/678.88 = 420.95/x
  3. Step 3: Cross multiply
    454.79x = 678.88 × 420.95
  4. Step 4: Simplify right side
    454.79x = 285,771.14
  5. Step 5: Solve for x
    x = 285,771.14/454.79
  6. Step 6: Final answer
    x = 628.37

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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.