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Finding the Fourth Proportional to 1,980.54, 2,970.82 and 811.18

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Solution

The fourth proportional to 1,980.54, 2,970.82 and 811.18 is: 1,216.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,980.54 : 2,970.82 = 811.18 : x
  2. Step 2: Convert to fraction form
    1,980.54/2,970.82 = 811.18/x
  3. Step 3: Cross multiply
    1,980.54x = 2,970.82 × 811.18
  4. Step 4: Simplify right side
    1,980.54x = 2,409,877.62
  5. Step 5: Solve for x
    x = 2,409,877.62/1,980.54
  6. Step 6: Final answer
    x = 1,216.78

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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.