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Finding the Fourth Proportional to 498.80, 747.30 and 421.40

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Solution

The fourth proportional to 498.80, 747.30 and 421.40 is: 631.34

Step by Step Solution

  1. Step 1: Write the proportion equation
    498.80 : 747.30 = 421.40 : x
  2. Step 2: Convert to fraction form
    498.80/747.30 = 421.40/x
  3. Step 3: Cross multiply
    498.80x = 747.30 × 421.40
  4. Step 4: Simplify right side
    498.80x = 314,912.22
  5. Step 5: Solve for x
    x = 314,912.22/498.80
  6. Step 6: Final answer
    x = 631.34

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.