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Finding the Fourth Proportional to 1,639.95, 2,459.92 and 485.70

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Solution

The fourth proportional to 1,639.95, 2,459.92 and 485.70 is: 728.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,639.95 : 2,459.92 = 485.70 : x
  2. Step 2: Convert to fraction form
    1,639.95/2,459.92 = 485.70/x
  3. Step 3: Cross multiply
    1,639.95x = 2,459.92 × 485.70
  4. Step 4: Simplify right side
    1,639.95x = 1,194,783.14
  5. Step 5: Solve for x
    x = 1,194,783.14/1,639.95
  6. Step 6: Final answer
    x = 728.55

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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.