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Finding the Fourth Proportional to 980.04, 1,343.10 and 978.40

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Solution

The fourth proportional to 980.04, 1,343.10 and 978.40 is: 1,340.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    980.04 : 1,343.10 = 978.40 : x
  2. Step 2: Convert to fraction form
    980.04/1,343.10 = 978.40/x
  3. Step 3: Cross multiply
    980.04x = 1,343.10 × 978.40
  4. Step 4: Simplify right side
    980.04x = 1,314,089.04
  5. Step 5: Solve for x
    x = 1,314,089.04/980.04
  6. Step 6: Final answer
    x = 1,340.85

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.