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Finding the Fourth Proportional to 890.78, 1,228.81 and 558.58

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Solution

The fourth proportional to 890.78, 1,228.81 and 558.58 is: 770.55

Step by Step Solution

  1. Step 1: Write the proportion equation
    890.78 : 1,228.81 = 558.58 : x
  2. Step 2: Convert to fraction form
    890.78/1,228.81 = 558.58/x
  3. Step 3: Cross multiply
    890.78x = 1,228.81 × 558.58
  4. Step 4: Simplify right side
    890.78x = 686,388.69
  5. Step 5: Solve for x
    x = 686,388.69/890.78
  6. Step 6: Final answer
    x = 770.55

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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.