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Finding the Fourth Proportional to 839.40, 1,158.21 and 490.02

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Solution

The fourth proportional to 839.40, 1,158.21 and 490.02 is: 676.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    839.40 : 1,158.21 = 490.02 : x
  2. Step 2: Convert to fraction form
    839.40/1,158.21 = 490.02/x
  3. Step 3: Cross multiply
    839.40x = 1,158.21 × 490.02
  4. Step 4: Simplify right side
    839.40x = 567,546.06
  5. Step 5: Solve for x
    x = 567,546.06/839.40
  6. Step 6: Final answer
    x = 676.13

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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.