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Finding the Fourth Proportional to 839.08, 1,157.70 and 489.70

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Solution

The fourth proportional to 839.08, 1,157.70 and 489.70 is: 675.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    839.08 : 1,157.70 = 489.70 : x
  2. Step 2: Convert to fraction form
    839.08/1,157.70 = 489.70/x
  3. Step 3: Cross multiply
    839.08x = 1,157.70 × 489.70
  4. Step 4: Simplify right side
    839.08x = 566,925.69
  5. Step 5: Solve for x
    x = 566,925.69/839.08
  6. Step 6: Final answer
    x = 675.65

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.