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Finding the Fourth Proportional to 1,387.34, 2,080.68 and 646.49

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Solution

The fourth proportional to 1,387.34, 2,080.68 and 646.49 is: 969.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,387.34 : 2,080.68 = 646.49 : x
  2. Step 2: Convert to fraction form
    1,387.34/2,080.68 = 646.49/x
  3. Step 3: Cross multiply
    1,387.34x = 2,080.68 × 646.49
  4. Step 4: Simplify right side
    1,387.34x = 1,345,138.81
  5. Step 5: Solve for x
    x = 1,345,138.81/1,387.34
  6. Step 6: Final answer
    x = 969.58

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1.5x scale

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.