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Finding the Fourth Proportional to 1,097.12, 1,642.80 and 840.80

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Solution

The fourth proportional to 1,097.12, 1,642.80 and 840.80 is: 1,258.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,097.12 : 1,642.80 = 840.80 : x
  2. Step 2: Convert to fraction form
    1,097.12/1,642.80 = 840.80/x
  3. Step 3: Cross multiply
    1,097.12x = 1,642.80 × 840.80
  4. Step 4: Simplify right side
    1,097.12x = 1,381,266.24
  5. Step 5: Solve for x
    x = 1,381,266.24/1,097.12
  6. Step 6: Final answer
    x = 1,258.99

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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.