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Finding the Fourth Proportional to 990.08, 1,366.08 and 680

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Solution

The fourth proportional to 990.08, 1,366.08 and 680 is: 938.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    990.08 : 1,366.08 = 680 : x
  2. Step 2: Convert to fraction form
    990.08/1,366.08 = 680/x
  3. Step 3: Cross multiply
    990.08x = 1,366.08 × 680
  4. Step 4: Simplify right side
    990.08x = 928,934.40
  5. Step 5: Solve for x
    x = 928,934.40/990.08
  6. Step 6: Final answer
    x = 938.24

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.