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Finding the Fourth Proportional to 679.80, 1,020.90 and 497.40

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Solution

The fourth proportional to 679.80, 1,020.90 and 497.40 is: 746.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    679.80 : 1,020.90 = 497.40 : x
  2. Step 2: Convert to fraction form
    679.80/1,020.90 = 497.40/x
  3. Step 3: Cross multiply
    679.80x = 1,020.90 × 497.40
  4. Step 4: Simplify right side
    679.80x = 507,795.66
  5. Step 5: Solve for x
    x = 507,795.66/679.80
  6. Step 6: Final answer
    x = 746.98

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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.