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Finding the Fourth Proportional to 1,314.20, 1,968.10 and 987.80

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Solution

The fourth proportional to 1,314.20, 1,968.10 and 987.80 is: 1,479.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,314.20 : 1,968.10 = 987.80 : x
  2. Step 2: Convert to fraction form
    1,314.20/1,968.10 = 987.80/x
  3. Step 3: Cross multiply
    1,314.20x = 1,968.10 × 987.80
  4. Step 4: Simplify right side
    1,314.20x = 1,944,089.18
  5. Step 5: Solve for x
    x = 1,944,089.18/1,314.20
  6. Step 6: Final answer
    x = 1,479.29

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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.