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Finding the Fourth Proportional to 628.80, 942.60 and 489.90

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Solution

The fourth proportional to 628.80, 942.60 and 489.90 is: 734.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    628.80 : 942.60 = 489.90 : x
  2. Step 2: Convert to fraction form
    628.80/942.60 = 489.90/x
  3. Step 3: Cross multiply
    628.80x = 942.60 × 489.90
  4. Step 4: Simplify right side
    628.80x = 461,779.74
  5. Step 5: Solve for x
    x = 461,779.74/628.80
  6. Step 6: Final answer
    x = 734.38

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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.