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Finding the Fourth Proportional to 890.64, 1,228.90 and 681.05

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Solution

The fourth proportional to 890.64, 1,228.90 and 681.05 is: 939.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    890.64 : 1,228.90 = 681.05 : x
  2. Step 2: Convert to fraction form
    890.64/1,228.90 = 681.05/x
  3. Step 3: Cross multiply
    890.64x = 1,228.90 × 681.05
  4. Step 4: Simplify right side
    890.64x = 836,942.35
  5. Step 5: Solve for x
    x = 836,942.35/890.64
  6. Step 6: Final answer
    x = 939.71

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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.