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Finding the Fourth Proportional to 751.20, 1,126.80 and 646.80

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Solution

The fourth proportional to 751.20, 1,126.80 and 646.80 is: 970.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    751.20 : 1,126.80 = 646.80 : x
  2. Step 2: Convert to fraction form
    751.20/1,126.80 = 646.80/x
  3. Step 3: Cross multiply
    751.20x = 1,126.80 × 646.80
  4. Step 4: Simplify right side
    751.20x = 728,814.24
  5. Step 5: Solve for x
    x = 728,814.24/751.20
  6. Step 6: Final answer
    x = 970.20

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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.