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Finding the Fourth Proportional to 890.21, 1,228.65 and 558.38

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Solution

The fourth proportional to 890.21, 1,228.65 and 558.38 is: 770.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    890.21 : 1,228.65 = 558.38 : x
  2. Step 2: Convert to fraction form
    890.21/1,228.65 = 558.38/x
  3. Step 3: Cross multiply
    890.21x = 1,228.65 × 558.38
  4. Step 4: Simplify right side
    890.21x = 686,053.59
  5. Step 5: Solve for x
    x = 686,053.59/890.21
  6. Step 6: Final answer
    x = 770.66

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Double scale
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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.