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Finding the Fourth Proportional to 1,386.70, 2,080.65 and 655.90

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Solution

The fourth proportional to 1,386.70, 2,080.65 and 655.90 is: 984.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,386.70 : 2,080.65 = 655.90 : x
  2. Step 2: Convert to fraction form
    1,386.70/2,080.65 = 655.90/x
  3. Step 3: Cross multiply
    1,386.70x = 2,080.65 × 655.90
  4. Step 4: Simplify right side
    1,386.70x = 1,364,698.34
  5. Step 5: Solve for x
    x = 1,364,698.34/1,386.70
  6. Step 6: Final answer
    x = 984.13

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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.