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Finding the Fourth Proportional to 980.65, 1,349.88 and 856.09

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Solution

The fourth proportional to 980.65, 1,349.88 and 856.09 is: 1,178.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    980.65 : 1,349.88 = 856.09 : x
  2. Step 2: Convert to fraction form
    980.65/1,349.88 = 856.09/x
  3. Step 3: Cross multiply
    980.65x = 1,349.88 × 856.09
  4. Step 4: Simplify right side
    980.65x = 1,155,612.02
  5. Step 5: Solve for x
    x = 1,155,612.02/980.65
  6. Step 6: Final answer
    x = 1,178.42

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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.