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Finding the Fourth Proportional to 1,340.80, 2,009.80 and 646.42

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Solution

The fourth proportional to 1,340.80, 2,009.80 and 646.42 is: 968.96

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,340.80 : 2,009.80 = 646.42 : x
  2. Step 2: Convert to fraction form
    1,340.80/2,009.80 = 646.42/x
  3. Step 3: Cross multiply
    1,340.80x = 2,009.80 × 646.42
  4. Step 4: Simplify right side
    1,340.80x = 1,299,174.92
  5. Step 5: Solve for x
    x = 1,299,174.92/1,340.80
  6. Step 6: Final answer
    x = 968.96

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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.